test(e2e): re-point the PIN lockout specs at the property that matters

Three specs asserted the OLD policy — that three wrong PINs lock an account —
which is exactly the behaviour the previous commit removed, because that threshold
sat below the per-(IP, name) throttle ceiling and so let any single IP lock any
guest whose display name is readable off the feed.

Rewritten to assert the distinction the fix introduces, which a status code alone
cannot show: both tiers answer 429, but only the account lock costs the VICTIM.
The new specs read the row via db.isPinLocked rather than the response, so:

- one IP hammering /recover is throttled and the account stays UNLOCKED;
- a distributed guesser (counter preloaded via db.setFailedPinAttempts, since no
  single source can reach the threshold any more) still trips the lock, and it
  holds even against the correct PIN;
- concurrent wrong PINs are all counted — the atomicity property the old parallel
  test was really about, now asserted on the counter instead of inferred from a
  429 that the throttle could equally have produced.

The UI spec asserts the user-visible half: after four wrong PINs Dave can still
get into his own account. It also now types the PIN digit by digit rather than
filling and clicking, because the 4th digit auto-submits (pin-auto-submit.spec.ts)
and doing both raced the button's disabled state.

The adversarial spec enables rate_limits_enabled for its own run — it is off by
default in this environment, so without that the throttle tier would silently not
be exercised — and restores it in afterEach so it cannot leak into other specs
sharing the stack.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.claude/settings.json

@@ -0,0 +1,9 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(cargo check *)",
+      "Bash(cargo clippy *)",
+      "Bash(git --no-pager diff *)"
+    ]
+  }
+}

.env.example

@@ -12,10 +12,32 @@ APP_ENV=production
 # ── Database ──────────────────────────────────────────────────────────────────
 # Set a strong password and keep it in sync between DATABASE_URL and
 # POSTGRES_PASSWORD. Generate one with: openssl rand -hex 24
+#
+# SET THIS BEFORE THE FIRST `docker compose up -d`. Postgres reads POSTGRES_PASSWORD
+# only when it initialises its data directory, on that very first boot. Change it
+# afterwards and the app authenticates with the new password against a volume still
+# holding the old one — a permanent restart loop ("password authentication failed").
+# The only ways out are restoring the old password or `docker compose down -v`, which
+# deletes the database, the media and the exports. In production the app refuses to
+# boot while this is still the placeholder below, so it cannot be missed by accident.
 DATABASE_URL=postgres://eventsnap:CHANGE_ME_use_a_strong_password@db:5432/eventsnap
 POSTGRES_USER=eventsnap
 POSTGRES_PASSWORD=CHANGE_ME_use_a_strong_password
 POSTGRES_DB=eventsnap
+# Connection pool size. Default 10. For a busy event (~100 guests polling the feed
+# + SSE + uploads at once) raise to ~30 so requests don't queue on a pool permit.
+# PAIRED WITH THE DB CONTAINER'S MEMORY LIMIT: 30 backends plus Postgres 16's default
+# shared_buffers is already snug in the 1G that docker-compose.yml allots the `db`
+# service. If you raise this, raise `db.deploy.resources.limits.memory` with it — an
+# OOM in Postgres doesn't degrade one feature, it takes the whole event down.
+DATABASE_MAX_CONNECTIONS=30
+
+# Log level. `info` is the right production default: at `debug` the tower-http trace
+# layer writes a line per request AND per response, which on a busy event is a large
+# multiple of the useful output. Container logs are capped at 10m x 3 per service
+# (docker-compose.yml), so a chatty level buys you a shorter history, not more of it.
+# To debug a live event: RUST_LOG=eventsnap_backend=debug docker compose up -d app
+RUST_LOG=info
 
 # ── Authentication ────────────────────────────────────────────────────────────
 # Generate with: openssl rand -hex 64
@@ -23,8 +45,14 @@ JWT_SECRET=change_me_to_a_random_64_byte_hex_string
 SESSION_EXPIRY_DAYS=30
 
 # Admin dashboard password (bcrypt hash).
-# Generate with: htpasswd -bnBC 12 "" yourpassword | tr -d ':\n'
-ADMIN_PASSWORD_HASH=$2y$12$placeholder_replace_me
+# Generate with an image the stack already pulls (htpasswd needs apache2-utils, which
+# a stock VPS does not have):
+#   docker run --rm caddy:2-alpine caddy hash-password --plaintext 'yourpassword'
+# IMPORTANT: keep the SINGLE QUOTES. A bcrypt hash is full of `$` (e.g. $2b$12$…$…),
+# and both Docker Compose's env_file interpolation and dotenvy's variable substitution
+# would otherwise eat the `$…` segments (reading them as unset vars) and corrupt the
+# hash — every admin login then 401s. Single quotes make both read it literally.
+ADMIN_PASSWORD_HASH='$2y$12$placeholder_replace_me'
 
 # ── Event ─────────────────────────────────────────────────────────────────────
 EVENT_NAME=Max & Maria's Wedding
@@ -36,19 +64,43 @@ MEDIA_PATH=/media
 # /media is publicly served, so exports here would be downloadable without auth.
 EXPORT_PATH=/exports
 
-# ── Upload limits ─────────────────────────────────────────────────────────────
-DEFAULT_MAX_IMAGE_SIZE_MB=20
-DEFAULT_MAX_VIDEO_SIZE_MB=500
-
-# ── Rate limiting ─────────────────────────────────────────────────────────────
-DEFAULT_UPLOAD_RATE_PER_HOUR=10
-DEFAULT_FEED_RATE_PER_MIN=60
-DEFAULT_EXPORT_RATE_PER_DAY=3
-
-# ── Capacity ──────────────────────────────────────────────────────────────────
-DEFAULT_ESTIMATED_GUEST_COUNT=100
-# Fraction of total storage that triggers the "low storage" warning (0.0–1.0)
-DEFAULT_QUOTA_TOLERANCE=0.75
+# ── Runtime settings (upload limits, rate limits, capacity) ───────────────────
+# NOTE: These are NOT environment variables. Upload size caps, rate limits, guest
+# count and quota tolerance are stored in the database `config` table (seeded once
+# at first boot) and changed at runtime from the ADMIN DASHBOARD — the backend does
+# not read them from .env. Setting them here has no effect. Current seeded defaults:
+#   upload rate      100 / hour / guest   (raised from 10 by migration 015)
+#   feed rate         60 / minute
+#   export rate        3 / day
+#   max image size    20 MB
+#   max video size   500 MB
+#   estimated guests 100
+#   quota tolerance  0.75  (see below — NOT a warning threshold)
+# Adjust these in the admin UI before the event if needed.
+#
+# quota_tolerance is the MULTIPLIER IN THE PER-USER QUOTA FORMULA, not the point at
+# which anything warns you:
+#
+#     per_user_limit = floor(free_disk * quota_tolerance / active_uploaders)
+#
+# It is recomputed against LIVE free space on every upload, so it self-throttles: guests
+# converge on a fixed point at tolerance/(1+tolerance) of the free space you started
+# with — 43% at 0.75, i.e. ~30 GB of a fresh 70 GB.
+#
+# Raising it therefore AUTHORISES GUESTS TO FILL MORE OF THE DISK. Setting 0.95 in the
+# belief that it means "warn me later" moves the fixed point to ~49% and eats the
+# headroom the keepsake needs — and the keepsake needs a lot, because Gallery.zip and
+# Memories.zip are each roughly a second copy of every original (both store media
+# uncompressed). Budget for media + 2x media, or move exports to their own volume.
+#
+# 0.75 is the tested default. Lower it if the box is tight; raise it only if you have
+# provisioned export headroom separately.
 
 # ── Workers ───────────────────────────────────────────────────────────────────
+# Number of parallel image/video compression workers. Default 2. This is the main
+# throughput bottleneck: with 2 workers a burst of uploads can take ~5s to appear.
+# For a large event (100+ guests) 4 is a good target — but each worker can run an
+# ffmpeg transcode, so if you raise this ALSO raise the app container's memory limit
+# in docker-compose.yml (`app.deploy.resources.limits.memory`) from 1G to ~2G, or a
+# burst of large videos can OOM the box and take Postgres down with it.
 COMPRESSION_WORKER_CONCURRENCY=2

.github/workflows/audit.yml

@@ -0,0 +1,73 @@
+# Dependency advisory scan.
+#
+# Lives in .github/workflows/ because Gitea Actions scans BOTH .gitea/workflows and
+# .github/workflows, and e2e.yml already proves this instance resolves `actions/*` from GitHub
+# (DEFAULT_ACTIONS_URL). Keeping one directory avoids a split where half the CI is invisible
+# depending on which convention you look under.
+#
+# Unlike the GitHub-hosted runners this workflow does NOT assume a preinstalled Rust toolchain —
+# the common Gitea runner images (gitea/runner-images, catthehacker/ubuntu) ship Node and Docker
+# but not cargo. So we install it explicitly instead of relying on the ambient environment.
+name: Audit
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+  schedule:
+    # New advisories land against unchanged code, so a push-only trigger would never see them.
+    - cron: '0 6 * * 1'
+
+jobs:
+  cargo-audit:
+    name: cargo audit (backend)
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Rust toolchain
+        run: |
+          if ! command -v cargo > /dev/null; then
+            curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --profile minimal
+            echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"
+          fi
+
+      - name: Cache cargo
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/bin
+          key: cargo-audit-${{ hashFiles('backend/Cargo.lock') }}
+          restore-keys: cargo-audit-
+
+      - name: Install cargo-audit
+        run: cargo install cargo-audit --locked || true
+
+      # `rsa` 0.9 (RUSTSEC-2023-0071, "Marvin") is a transitive dep of the SQLx MySQL driver that
+      # this app never exercises: auth is HS256 + bcrypt, and the only database is Postgres. There
+      # is no patched release, so failing the build on it would mean a permanently red pipeline
+      # that everyone learns to ignore — which is worse than not scanning at all. Ignore it
+      # SPECIFICALLY, so that any OTHER advisory still fails the job.
+      - name: Audit
+        working-directory: ./backend
+        run: cargo audit --deny warnings --ignore RUSTSEC-2023-0071
+
+  npm-audit:
+    name: npm audit (frontend)
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+      - name: Install deps
+        working-directory: ./frontend
+        run: npm install
+      # Production dependencies only: a dev-only advisory (build tooling, test runners) can't be
+      # reached by a guest at the party, and gating merges on it just trains people to skip the gate.
+      - name: Audit
+        working-directory: ./frontend
+        run: npm audit --omit=dev --audit-level=high

.github/workflows/checks.yml

@@ -0,0 +1,129 @@
+# The checks that were only ever running on a laptop.
+#
+# Before this file, CI ran Playwright (chromium-desktop) and the dependency audit — and nothing
+# else. `cargo test` (40 tests), the frontend vitest suite (5 files, including the offline
+# upload-queue and auth-token logic), svelte-check, and the e2e typecheck were all green on a
+# developer's machine and gated NOTHING. A check that only ever runs locally is not running.
+#
+# In .github/workflows/ because Gitea Actions scans it too (see audit.yml). Rust is installed
+# explicitly: the common Gitea runner images ship Node and Docker, not cargo.
+name: Checks
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+jobs:
+  backend:
+    name: Backend — cargo test + clippy + fmt
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Rust toolchain
+        run: |
+          if ! command -v cargo > /dev/null; then
+            curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --profile minimal
+            echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"
+          fi
+          rustup component add clippy rustfmt
+
+      - uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            backend/target
+          key: cargo-${{ hashFiles('backend/Cargo.lock') }}
+          restore-keys: cargo-
+
+      # SQLx runs its queries against a live database at TEST time (see backend/tests/), so the
+      # DB-backed tests need one. The pure unit tests don't care, but starting it unconditionally
+      # keeps the job simple and honest about what it covers.
+      - name: Start Postgres
+        run: |
+          docker run -d --name ci-pg -p 5432:5432 \
+            -e POSTGRES_PASSWORD=postgres -e POSTGRES_DB=eventsnap_ci \
+            postgres:16-alpine
+          for _ in $(seq 1 30); do
+            docker exec ci-pg pg_isready -U postgres > /dev/null 2>&1 && break
+            sleep 1
+          done
+
+      - name: Test
+        working-directory: ./backend
+        env:
+          DATABASE_URL: postgres://postgres:postgres@localhost:5432/eventsnap_ci
+        # `#[sqlx::test]` creates a fresh database per test and opens its own pool; run at unbounded
+        # parallelism against a default `max_connections=100` Postgres, a full suite can exhaust the
+        # server's connection slots and fail with PoolTimedOut — a pure infra flake, not a real
+        # failure. Cap the concurrency so the gate stays trustworthy on a loaded runner.
+        run: cargo test --all-features -- --test-threads=8
+
+      - name: Clippy
+        working-directory: ./backend
+        run: cargo clippy --all-targets -- -D warnings
+
+      - name: Format
+        working-directory: ./backend
+        run: cargo fmt --check
+
+  frontend:
+    name: Frontend — vitest + svelte-check
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+          cache: 'npm'
+          cache-dependency-path: 'frontend/package-lock.json'
+
+      - name: Install deps
+        working-directory: ./frontend
+        run: npm ci || npm install
+
+      - name: Unit tests
+        working-directory: ./frontend
+        run: npm run test:unit
+
+      - name: svelte-check
+        working-directory: ./frontend
+        run: npx svelte-check --threshold error
+
+      - name: ESLint
+        working-directory: ./frontend
+        run: npm run lint
+
+      - name: Prettier
+        working-directory: ./frontend
+        run: npm run format:check
+
+  e2e-typecheck:
+    name: E2E — typecheck + lint
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+      - name: Install deps
+        working-directory: ./e2e
+        run: npm install
+      # Playwright TRANSPILES specs without typechecking them, so a type error in a spec is
+      # invisible until the assertion it guards silently does the wrong thing at runtime.
+      - name: tsc --noEmit
+        working-directory: ./e2e
+        run: npx tsc --noEmit
+
+      - name: ESLint
+        working-directory: ./e2e
+        run: npm run lint
+
+      - name: Prettier
+        working-directory: ./e2e
+        run: npm run format:check

.github/workflows/e2e.yml

@@ -7,7 +7,7 @@ on:
 
 jobs:
   e2e:
-    name: Playwright E2E (chromium-desktop)
+    name: Playwright E2E (chromium + webkit)
     runs-on: ubuntu-latest
     timeout-minutes: 30
     steps:
@@ -25,7 +25,7 @@ jobs:
 
       - name: Install Playwright browsers
         working-directory: ./e2e
-        run: npx playwright install --with-deps chromium
+        run: npx playwright install --with-deps chromium webkit
 
       - name: Bring up the test stack
         working-directory: ./e2e
@@ -46,6 +46,30 @@ jobs:
         working-directory: ./e2e
         run: npm run test:e2e -- --project=chromium-desktop
 
+      # 09-mobile is `testIgnore`d on chromium-desktop (it needs hasTouch + a phone viewport), so
+      # running only that project left 22 tests — focus traps, touch targets, safe-area insets,
+      # viewport reflow, upload-cancel — never executing in CI. On a phone-first event app, where
+      # essentially every real guest is on a phone, that was the wrong half of the suite to skip.
+      - name: Run E2E tests (mobile)
+        working-directory: ./e2e
+        run: npm run test:e2e -- --project=chromium-mobile
+
+      # iOS Safari is the app's stated primary user (a wedding guest opening a QR link), and
+      # WebKit is the ONLY engine here that reproduces two of its behaviours:
+      #   - it enforces X-Frame-Options on the download iframe, so a site-wide `DENY` makes the
+      #     keepsake download silently do nothing. Blink hands attachments to the download
+      #     manager first and never notices. That shipped once already.
+      #   - it abandons a <video> load without a 206 response to its Range probe.
+      # Both regressions are invisible to every Chromium project, so running WebKit is what
+      # actually gates them on a PR rather than on someone remembering to test locally.
+      #
+      # The project is scoped in playwright.config.ts to the journeys a guest walks
+      # (01-auth, 02-upload, 03-feed, 06-export); four IndexedDB-blob tests skip themselves
+      # there — see helpers/webkit.ts for why that is the harness and not the app.
+      - name: Run E2E tests (webkit / iOS)
+        working-directory: ./e2e
+        run: npm run test:e2e -- --project=webkit-iphone
+
       - name: Upload Playwright report
         if: failure()
         uses: actions/upload-artifact@v4

.gitignore

@@ -13,8 +13,16 @@ frontend/build/
 frontend/export-viewer/node_modules/
 frontend/export-viewer/.svelte-kit/
 
-# Media uploads (mounted volume in production)
-media/
+# Media uploads. In production these live in the `media_data` DOCKER VOLUME, never in the
+# working tree — so this pattern is anchored to the repo root and exists only for a local
+# bind-mount experiment.
+#
+# It used to read `media/`, unanchored, which matches a directory of that name at ANY depth.
+# The only one in the repo is `e2e/fixtures/media/`, so the rule's entire practical effect was
+# to keep every E2E fixture untracked: a fresh clone got the specs and none of the images or
+# videos they read. `.github/workflows/e2e.yml` does a plain checkout and generates nothing, so
+# the committed CI job could not have run the upload, video or export suites at all.
+/media/
 
 # Playwright E2E suite — runtime artifacts (the suite itself is committed)
 e2e/node_modules/
@@ -29,3 +37,6 @@ e2e/.env.test
 # OS
 .DS_Store
 Thumbs.db
+
+# Claude Code personal (per-user) settings — shared settings.json IS committed
+.claude/settings.local.json

Caddyfile

@@ -9,33 +9,63 @@
 	header {
 		Strict-Transport-Security "max-age=31536000; includeSubDomains"
 		X-Content-Type-Options "nosniff"
-		X-Frame-Options "DENY"
 		Referrer-Policy "strict-origin-when-cross-origin"
 	}
 
+	# X-Frame-Options: DENY everywhere EXCEPT the keepsake download endpoints, which
+	# are navigated in a HIDDEN, SAME-ORIGIN iframe so a 404/429 can't unload the PWA
+	# (see frontend/src/routes/export/+page.svelte). WebKit enforces XFO *before*
+	# honouring Content-Disposition, so a blanket DENY makes the download silently do
+	# nothing on iOS Safari — the app's primary platform. SAMEORIGIN still blocks
+	# cross-origin framing.
+	#
+	# Split into two disjoint matchers rather than an override: Caddy applies the
+	# FIRST header directive outermost, so it wins on write — a later, more specific
+	# `header` would be silently ignored.
+	@framable path /api/v1/export/zip /api/v1/export/html
+	@not_framable not path /api/v1/export/zip /api/v1/export/html
+	header @framable X-Frame-Options "SAMEORIGIN"
+	header @not_framable X-Frame-Options "DENY"
+
 	# SvelteKit frontend — static assets with long-lived cache (content-hashed filenames)
 	@hashed_assets path_regexp hashed /_app/immutable/.*\.[a-f0-9]{8,}\.(js|css|woff2)$
 	header @hashed_assets Cache-Control "public, max-age=31536000, immutable"
 
-	# Media previews and thumbnails
-	@previews path /media/previews/* /media/thumbnails/*
-	header @previews Cache-Control "public, max-age=3600"
+	# Preview/thumbnail images. These are served by the app through a visibility-checked
+	# alias (/api/v1/upload/{id}/{preview,thumbnail}) so moderation can revoke access;
+	# the app serves no /media route at all, so there is no direct path to the bytes.
+	# Privately cacheable for a short window (the app sets the same header; this is the
+	# edge carve-out from the blanket no-store below). Kept short so a moderated image
+	# stops being served to a direct-URL holder promptly.
+	@media_api path /api/v1/upload/*/preview /api/v1/upload/*/thumbnail
+	header @media_api Cache-Control "private, max-age=300"
 
-	# Original media files (private — only host can download). Force download
-	# rather than inline rendering as defense-in-depth against any future
-	# content-type confusion (previews/thumbnails are re-encoded and stay inline).
-	@originals path /media/originals/*
-	header @originals Cache-Control "private, max-age=86400"
-	header @originals Content-Disposition "attachment"
-
-	# API — never cache
-	@api path /api/*
+	# API and health — never cache, EXCEPT the gated image routes above. A cached health
+	# response would report the last known state rather than the current one.
+	@api {
+		path /api/* /health
+		not path /api/v1/upload/*/preview /api/v1/upload/*/thumbnail
+	}
 	header @api Cache-Control "no-store"
 
-	# Route API and media requests to the Rust backend
+	# Route API and media requests to the Rust backend.
+	#
+	# The app serves no /media route at all (see the note in backend/src/main.rs) — media
+	# bytes are reachable only through the visibility-checked /api/v1/upload aliases, so
+	# /media/* forwards to a plain 404. The proxy line is kept deliberately: it means the
+	# edge faithfully hands /media to the app, so if a future change ever re-introduces a
+	# static media route the e2e gating specs see it here exactly as production would,
+	# instead of being masked by the SvelteKit 404 page.
 	reverse_proxy /api/* app:3000
 	reverse_proxy /media/* app:3000
 
+	# The backend registers /health on its ROOT router, not under /api/v1, so it needs its
+	# own line — without it the catch-all below hands /health to SvelteKit, which has no
+	# such route and returns its 404 page. That made the documented post-deploy check
+	# (`curl -fsS https://DOMAIN/health`) fail 100% of the time on a perfectly healthy
+	# stack. e2e/Caddyfile.test has always carried this line; production never did.
+	reverse_proxy /health app:3000
+
 	# Everything else goes to SvelteKit frontend
 	reverse_proxy frontend:3001
 }

PROJECT.md

@@ -709,7 +709,7 @@ CREATE TABLE config (
 INSERT INTO config (key, value) VALUES
     ('max_image_size_mb',       '20'),
     ('max_video_size_mb',       '500'),
-    ('upload_rate_per_hour',    '10'),
+    ('upload_rate_per_hour',    '100'),  -- raised from 10 in migration 015 (guests upload bursts of 10-20)
     ('feed_rate_per_min',       '60'),
     ('export_rate_per_day',     '3'),
     ('quota_tolerance',         '0.75'),
@@ -1133,16 +1133,19 @@ eventsnap/
 
 ### Backup Strategy
 
-```bash
-# Daily (e.g. as a separate Compose service or cron on the VPS)
-pg_dump $DATABASE_URL | gzip > /media/backups/db_$(date +%Y-%m-%d).sql.gz
+Three artefacts in three places: the database, the `media_data` volume
+(originals + derivatives), and the **separate** `exports_data` volume. See
+[README.md](README.md#backup) for the exact commands.
 
-# Weekly: rsync /media volume to Hetzner Storage Box
-rsync -az /opt/eventsnap/media/ \
-  user@u123456.your-storagebox.de:backup/eventsnap/
-```
+Everything runs through `docker compose` / `docker run`, because `DATABASE_URL`
+and the `/media` and `/exports` paths only exist inside the compose network —
+they are not host paths, and `DATABASE_URL` is never exported into an operator's
+shell.
 
-The `/media` volume contains originals, previews, thumbnails, generated exports, and DB backups — a single volume to back up.
+Export archives are deliberately outside `MEDIA_PATH` (`EXPORT_PATH=/exports`): a
+keepsake contains every photo in the event, and keeping it off the media tree is
+what stops it being reachable except through the ticket-gated handler. A backup
+of the media volume alone silently loses every generated keepsake.
 
 ---
 

README.md

@@ -34,7 +34,6 @@ A guest scans the QR code on their way in, types their name, and is immediately
 ### Planned (v1.x)
 
 - Individual file download button
-- Low-disk alert (< 10 GB free)
 - Event banner / cover image
 - Chunked resumable upload for large videos
 - Host-curated story highlights
@@ -98,33 +97,135 @@ eventsnap/
 git clone https://git.mc02.dev/fabi/EventSnap.git eventsnap
 cd eventsnap
 
-# 2. Configure environment
+# 2. Configure environment — set EVERY secret NOW, before step 3.
 cp .env.example .env
-nano .env   # set DOMAIN, JWT_SECRET, ADMIN_PASSWORD_HASH, EVENT_NAME, etc.
+nano .env   # DOMAIN, EVENT_NAME, EVENT_SLUG,
+            # JWT_SECRET, ADMIN_PASSWORD_HASH,
+            # POSTGRES_PASSWORD *and* the same password inside DATABASE_URL
+            # (see "Generate required secrets" below)
 
 # 3. Start the stack
 docker compose up -d
 ```
 
+> **Set every secret before step 3 — `POSTGRES_PASSWORD` especially.** Postgres reads it **only
+> when it initialises its data directory**, which happens on the very first `docker compose up -d`.
+> Changing it in `.env` afterwards does not change the stored password: the app then authenticates
+> with the new one against a volume holding the old one, and you get a permanent restart loop with
+> `password authentication failed for user "eventsnap"`. The only fixes are restoring the old
+> password or `docker compose down -v`, which **deletes the database, the media and the exports**.
+> Getting it right once, up front, costs nothing; getting it wrong costs the volume.
+
 Caddy automatically obtains a Let's Encrypt certificate on first start. The app is live at `https://DOMAIN` within ~30 seconds.
 
-> **If the site never comes up:** with `APP_ENV=production` the backend **refuses to boot** while `JWT_SECRET`/`ADMIN_PASSWORD_HASH` still hold the `.env.example` placeholders (this is deliberate — a publicly-known signing key is worse than downtime). Caddy then waits on the unhealthy `app` container and never serves. Check `docker compose logs app` — a "Refusing to start … placeholder …" line means you skipped step 2. Rotate the secrets (see below) and restart.
+> **If the site never comes up:** with `APP_ENV=production` the backend **refuses to boot** while
+> `JWT_SECRET`, `ADMIN_PASSWORD_HASH` or the password inside `DATABASE_URL` still hold the
+> `.env.example` placeholders (this is deliberate — a publicly-known signing key or database
+> password is worse than downtime). Caddy then waits on the unhealthy `app` container and never
+> serves. Check `docker compose logs app` — a "Refusing to start … placeholder …" line lists
+> **every** unset secret at once, so one edit fixes them all.
+>
+> **If it comes up but keeps restarting with `password authentication failed for user
+> "eventsnap"`:** `POSTGRES_PASSWORD` was changed after the database volume was created. Postgres
+> applies that variable only at initialisation, so `.env` and the stored password have drifted
+> apart permanently. `docker compose logs app` spells this out. Before the event, with nothing
+> worth keeping:
+>
+> ```bash
+> docker compose down -v && docker compose up -d   # -v DELETES db + media + exports. No undo.
+> ```
+>
+> **Once the event has real data, never do that.** Put the original password back into
+> `DATABASE_URL`, or change the stored one instead:
+>
+> ```bash
+> docker compose exec db psql -U "$POSTGRES_USER" -c \
+>   "ALTER ROLE eventsnap WITH PASSWORD 'the-password-now-in-your-.env';"
+> ```
 
 > **Production note:** `docker compose up -d` does **not** expose the database — Postgres is reachable only on the internal Docker network. For local development where you need host access to Postgres, opt into the dev overlay explicitly:
 > ```bash
 > docker compose -f docker-compose.yml -f docker-compose.dev.yml up
 > ```
 
+### Updating an existing deployment
+
+> **`docker compose up -d` alone will NOT deploy your changes.** `app` and `frontend` are
+> `build:` services with no published image tag, and Compose has no source-change detection:
+> if an image with that name already exists it is reused. After a `git pull` the command
+> reports `Container … Running`, changes nothing, and **exits 0** — so a deploy that shipped
+> nothing looks exactly like a successful one. `--build` is what makes it real.
+
+```bash
+cd /path/to/eventsnap
+
+# 1. Back up first — migrations run automatically on boot and are not reversible in place.
+#    (See "Backup" below; the database dump is the one that matters here.)
+
+# 2. Fetch the new code.
+git pull
+
+# 3. Rebuild and restart the application services. --build is NOT optional.
+docker compose up -d --build
+
+# 4. Apply any Caddyfile change. Step 3 does NOT do this — see the warning below.
+docker compose up -d --force-recreate caddy
+
+# 5. Confirm the app came back up. Anything other than "ok" means check the logs.
+curl -fsS https://DOMAIN/health && echo
+
+# 6. Confirm a NEW image was actually built. Note the IMAGE ID before you start and
+#    compare — it must have changed. (Ignore the CREATED column; it reports the base
+#    layer's age, not this build's.) An unchanged ID means step 3 ran without --build
+#    and you are still serving the old code.
+docker compose images app frontend
+```
+
+Migrations are applied by the backend on startup, so step 3 covers them. If `app` stays
+unhealthy afterwards, `docker compose logs app` will name the failing migration — and note
+that a migration applied by a *newer* build is not removed by checking out an older commit,
+so rolling back code without restoring the database snapshot from step 1 leaves the schema
+ahead of the binary and the app refusing to boot.
+
+> **Why step 4 exists.** `--build` only rebuilds services that have a `build:` section, and
+> `caddy` is a pinned upstream image. Compose decides whether to recreate a container from its
+> *config hash*, which covers the mount **specification** (`./Caddyfile:/etc/caddy/Caddyfile:ro`)
+> but **not the file's contents** — so a `git pull` that changes `./Caddyfile` produces no
+> delta, Compose reports `Running`, and Caddy keeps serving its old config indefinitely. Exit
+> code 0 throughout.
+>
+> That is not hypothetical: the fix that made the keepsake download work on iOS
+> (`137c4ee`) touched the Caddyfile and four e2e files and nothing else, so **all** of its
+> production effect lives in that one file. Without step 4 you deploy it, watch both image IDs
+> change, and iOS downloads stay broken.
+>
+> `--force-recreate` rather than `restart` or `caddy reload`: the bind mount is resolved to an
+> **inode** when the container is created, and `git pull` replaces the file instead of editing
+> it in place, so the container can still be bound to the old, now-unlinked inode. A restart
+> then re-reads the stale content. Recreating the container re-resolves the path.
+
+`db` is never touched, and recreating `caddy` does not disturb the `caddy_data` volume, so the
+TLS certificate and all data volumes survive.
+
 ### Generate required secrets
 
 ```bash
 # JWT secret (64 random bytes)
 openssl rand -hex 64
 
-# Admin password hash (bcrypt, cost 12)
-htpasswd -bnBC 12 "" yourpassword | tr -d ':\n'
+# Database password (goes in BOTH DATABASE_URL and POSTGRES_PASSWORD)
+openssl rand -hex 24
+
+# Admin password hash (bcrypt). Uses an image the stack already pulls, so it needs
+# nothing installed on the host — `htpasswd` lives in apache2-utils, which a stock
+# VPS does not have. Emits cost 14 rather than 12; that is fine (admin login is
+# rate-limited and hashed off the async runtime), and any $2a/$2b/$2y hash verifies.
+docker run --rm caddy:2-alpine caddy hash-password --plaintext 'yourpassword'
 ```
 
+Wrap the resulting hash in **single quotes** in `.env` — see the note there; a bcrypt
+hash is full of `$`, and both Compose and dotenvy would otherwise eat those segments.
+
 ### Environment Variables
 
 See [.env.example](.env.example) for the full list with descriptions and defaults. Key variables:
@@ -162,26 +263,201 @@ See [.env.example](.env.example) for the full list with descriptions and default
 └────────┘
 ```
 
-- `/api/*` and `/media/*` → Rust backend
+- `/api/*` → Rust backend
 - Everything else → SvelteKit frontend (`adapter-node`)
-- Named volumes: `postgres_data`, `media_data`, `caddy_data`
+- Named volumes: `postgres_data`, `media_data`, `exports_data`, `caddy_data`
+
+Media is **not** served as static files. Every image goes through a
+visibility-checked alias (`/api/v1/upload/{id}/{preview,display,thumbnail,original}`)
+so a host takedown or a ban actually revokes access to the bytes.
+
+---
+
+## Sizing the disk
+
+`postgres_data`, `media_data` and `exports_data` are all Docker named volumes under
+`/var/lib/docker/volumes`, so **they share one filesystem**. Filling it does not
+degrade one subsystem — Postgres stops being able to write and the whole event goes
+down.
+
+Uploads are self-limiting. `per_user_limit = free_disk × quota_tolerance ÷
+active_uploaders` is recomputed against live free space on every upload, so guests
+converge on a fixed point at `tolerance / (1 + tolerance)` of the free space you
+started with — **43%** at the default 0.75. On an 80 GB box with ~70 GB free after
+the OS and images, media settles at ~30 GB and stops.
+
+**The keepsake is what the 80 GB baseline does not cover.** `Gallery.zip` and
+`Memories.zip` are built concurrently and each is roughly a second copy of every
+original: both write their media `Compression::Stored`, and `Memories.zip` streams the
+untouched original for every video and for every image at or under 5 MB. So a release
+wants room for **two more copies of the gallery** on top of the gallery itself.
+
+| Stage | Used | Free (80 GB box) |
+|---|---|---|
+| Fresh box (OS + images) | ~10 GB | ~70 GB |
+| Guests reach the quota fixed point | ~40 GB | ~40 GB |
+| Host releases → both archives | ~100 GB | **ENOSPC** |
+
+Two ways to size for it:
+
+- **Provision ~3× your expected media** on one volume (media + two archives), or
+- **give `exports_data` its own volume** so a full export cannot reach Postgres, and
+  size that one at ~2× expected media.
+
+This is no longer silent. The export refuses up front with the two numbers rather than
+hitting ENOSPC halfway through a multi-GB write, a rebuild reclaims the superseded
+generation before it starts (so peak is one generation, not two), and the host
+dashboard warns as soon as the keepsake would not fit — which is the only point at
+which anyone can still do something about it.
 
 ---
 
 ## Backup
 
-```bash
-# Database snapshot
-pg_dump $DATABASE_URL | gzip > /media/backups/db_$(date +%Y-%m-%d).sql.gz
+There are **three** things to back up, and they live in three different places.
+`DATABASE_URL` and the container paths (`/media`, `/exports`) are meaningful only
+*inside* the compose network — they are not host paths, and `DATABASE_URL` is
+never exported into an operator's shell — so every command below runs through
+`docker compose` from the repo directory.
 
-# Weekly offsite sync (Hetzner Storage Box or similar)
-rsync -az /opt/eventsnap/media/ user@storagebox.example.com:backup/eventsnap/
+```bash
+# 1. Database snapshot. Runs pg_dump inside the db container (the app image has no
+#    postgres client), reading credentials from the compose environment.
+#    --clean --if-exists makes the dump SELF-CLEANING: without it the restore below
+#    aborts on the first "already exists" against a database that has ever booted,
+#    which is every database you would actually want to restore over.
+mkdir -p ./backups
+docker compose exec -T db \
+  sh -c 'pg_dump --clean --if-exists -U "$POSTGRES_USER" "$POSTGRES_DB"' \
+  | gzip > ./backups/db_$(date +%Y-%m-%d).sql.gz
+
+# 2. Uploaded media (originals + derivatives) out of the named volume.
+#    NOTE the mountpoint is /src, not /media: if the volume is ever empty, Docker
+#    pre-populates a fresh mount from the image's own directory, and alpine ships a
+#    /media containing cdrom/floppy/usb. Mounting somewhere the image has nothing
+#    avoids silently tarring (and polluting the volume with) those.
+docker run --rm \
+  -v eventsnap_media_data:/src:ro -v "$PWD/backups":/backup \
+  alpine tar czf /backup/media_$(date +%Y-%m-%d).tar.gz -C /src .
+
+# 3. Export archives — a SEPARATE volume (see the security note below).
+docker run --rm \
+  -v eventsnap_exports_data:/src:ro -v "$PWD/backups":/backup \
+  alpine tar czf /backup/exports_$(date +%Y-%m-%d).tar.gz -C /src .
+
+# Offsite sync of the three artefacts above.
+rsync -az ./backups/ user@storagebox.example.com:backup/eventsnap/
 ```
 
-The `/media` volume holds originals, previews, thumbnails, exports, and DB backups — a single path to back up.
+Volume names are prefixed with the compose project name — `eventsnap_` if you run
+from a directory called `eventsnap`. Confirm yours with `docker volume ls`.
+
+> **Exports are deliberately NOT under `/media`.** They live on their own
+> `exports_data` volume (`EXPORT_PATH=/exports`) because a keepsake archive
+> contains every photo in the event; keeping it outside the media tree is what
+> stops it being reachable except through the ticket-gated download handler.
+> Backing up only the media volume therefore loses every generated keepsake.
+
+### When to run it
+
+**A nightly cron is the wrong shape for this app.** Every irreplaceable byte is
+created inside one eight-hour window, and nobody can retake a wedding. Run the three
+commands above:
+
+1. **The night of the event**, once uploads have stopped. This is the backup that
+   matters; everything else is a formality.
+2. **After the host releases the gallery**, so the generated keepsake is captured too.
+3. Weekly thereafter, until the event is archived and torn down.
+
+Take the DB dump and the media tarball **back to back**, without uploads in flight
+between them. Upload rows reference files by path — a database from 22:00 and a media
+volume from 23:00 gives you rows pointing at files the dump doesn't know about, and
+rows whose files aren't in the tarball. Locking uploads from the host dashboard first
+(**Uploads sperren**) makes the pair genuinely consistent.
 
 ---
 
+## Restore
+
+An untested backup is not a backup. Run this once against a scratch host **before**
+the event — it is roughly ten minutes, and it is the only way to find out that your
+tarball is empty or your dump is truncated while that is still a small problem.
+
+```bash
+# 0. Stop the app FIRST. Migrations run on boot and a live pool will fight the
+#    restore — a booting app against a half-restored schema can leave the migration
+#    table and the schema disagreeing, which is its own recovery problem.
+#    Leave `db` running: the dump is restored through it.
+docker compose stop app caddy
+
+# 1. Database. The dump carries its own DROPs (step 1 of Backup), so this replaces
+#    rather than collides. A dump taken WITHOUT --clean --if-exists will abort here
+#    on the first "already exists" — restore that one into a fresh empty database
+#    instead.
+gunzip -c ./backups/db_2026-07-29.sql.gz \
+  | docker compose exec -T db \
+      sh -c 'psql -U "$POSTGRES_USER" -d "$POSTGRES_DB" --set ON_ERROR_STOP=1'
+
+# 2. Media. NOTE the `--numeric-owner` and the chown: the app runs as a
+#    NON-ROOT user (uid 100, gid 101 — `addgroup -S app && adduser -S app`), and a
+#    restore that lands root-owned files makes every upload fail with EACCES deep in
+#    the write path, surfacing to the guest as a generic 500 with nothing in the UI
+#    to suggest permissions. The explicit chown is what guarantees it — BusyBox tar
+#    (which is what `alpine` ships) has no --same-owner, and restores ownership only
+#    because it runs as root here.
+docker run --rm \
+  -v eventsnap_media_data:/dst -v "$PWD/backups":/backup:ro \
+  alpine sh -c 'tar xzf /backup/media_2026-07-29.tar.gz -C /dst \
+                    --numeric-owner && chown -R 100:101 /dst'
+
+# 3. Exports. Same volume-name caveat, same ownership rules.
+docker run --rm \
+  -v eventsnap_exports_data:/dst -v "$PWD/backups":/backup:ro \
+  alpine sh -c 'tar xzf /backup/exports_2026-07-29.tar.gz -C /dst \
+                    --numeric-owner && chown -R 100:101 /dst'
+
+# 4. Back up. Migrations run, then export recovery re-arms any keepsake whose file
+#    didn't come back with the volume.
+docker compose up -d app caddy
+docker compose logs -f app        # watch for "migrations applied"
+
+# 5. Verify — all three, not just the first.
+curl -fsS https://DOMAIN/health && echo            # → ok
+#   … then sign in as host and confirm the feed renders images (proves the media
+#   volume restored AND is readable by uid 100), and that the keepsake downloads.
+```
+
+If the media volume restored but images 404 while the feed lists them, the paths are
+there and the bytes aren't — check `docker compose exec app ls -ln /media/originals`
+and confirm both the files and the `100:101` ownership.
+
+The restore is deliberately **not** automated. It is rare, destructive, and the one
+operation where a script that half-works is worse than a checklist someone reads.
+
+---
+
+## Running the backend test suite
+
+```bash
+cd backend
+
+# The DB-backed integration tests (backend/tests/) need a live Postgres. `#[sqlx::test]` creates a
+# throwaway database per test and runs backend/migrations/ into it — it does NOT touch this one's data.
+docker run -d --name eventsnap-test-pg -p 55433:5432 \
+  -e POSTGRES_PASSWORD=postgres -e POSTGRES_DB=eventsnap postgres:16-alpine
+
+export DATABASE_URL=postgres://postgres:postgres@localhost:55433/eventsnap
+cargo test        # 44 unit + 12 DB-backed
+cargo clippy --all-targets -- -D warnings
+```
+
+**`cargo test` requires `DATABASE_URL`** — without it the integration tests panic rather than skip.
+That is deliberate. The riskiest code in this repo is SQL (the export epoch state machine, the
+atomic quota increment, the `FOR SHARE` upload lock), and for a long time *not one line of it* was
+executed by `cargo test` — every backend test was a pure-function test, so the tests clustered
+tightly around the code that could not break and stopped exactly where it started to. Tests that
+silently skip when the database is absent recreate that hole; they were meant to be a gate.
+
 ## Running the E2E test suite
 
 Playwright-based end-to-end tests live in [`e2e/`](e2e/). They spin up an isolated docker-compose stack (Postgres on `:55432`, Caddy on `:3101`) and exercise the SvelteKit frontend against the real Rust backend with rate limits disabled.
@@ -198,7 +474,14 @@ npm run stack:down            # tear it down
 
 See [`e2e/README.md`](e2e/README.md) for the full UA matrix, Samsung Internet escalation tiers, and the Phase 2/3 roadmap.
 
-CI runs this on every PR — see [`.github/workflows/e2e.yml`](.github/workflows/e2e.yml).
+CI runs this on every PR — see [`.github/workflows/e2e.yml`](.github/workflows/e2e.yml) (desktop **and**
+mobile projects), plus [`checks.yml`](.github/workflows/checks.yml) for `cargo test`/clippy, the frontend
+unit tests, svelte-check and the e2e typecheck, and [`audit.yml`](.github/workflows/audit.yml) for
+dependency advisories.
+
+**Playwright runs with `retries: 0`, including in CI.** This repo's real bugs are races, and from the
+outside a race is indistinguishable from a flake — so a retry silently resolves that ambiguity in
+favour of "flake" every time. A flake here is a bug report; treat it as one.
 
 ---
 
@@ -225,7 +508,7 @@ Open:
 - [ ] SSE delta-fetch on foreground reconnect (scaffolded in [sse.ts](frontend/src/lib/sse.ts), not wired)
 - [ ] Live diashow / slideshow mode — see [docs/CONCEPT_DIASHOW.md](docs/CONCEPT_DIASHOW.md)
 - [ ] Individual file download button per post
-- [ ] Low-disk alert (< 10 GB free)
+- [x] Low-disk alert — host dashboard warns below 10 GB free, or whenever the keepsake would not fit
 - [ ] Event banner / cover image
 - [ ] Chunked resumable upload for files > 100 MB
 - [ ] Shared Tailwind config between main app and export-viewer

backend/Cargo.lock

@@ -65,56 +65,6 @@ dependencies = [
  "libc",
 ]
 
-[[package]]
-name = "anstream"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "824a212faf96e9acacdbd09febd34438f8f711fb84e09a8916013cd7815ca28d"
-dependencies = [
- "anstyle",
- "anstyle-parse",
- "anstyle-query",
- "anstyle-wincon",
- "colorchoice",
- "is_terminal_polyfill",
- "utf8parse",
-]
-
-[[package]]
-name = "anstyle"
-version = "1.0.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "940b3a0ca603d1eade50a4846a2afffd5ef57a9feac2c0e2ec2e14f9ead76000"
-
-[[package]]
-name = "anstyle-parse"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "52ce7f38b242319f7cabaa6813055467063ecdc9d355bbb4ce0c68908cd8130e"
-dependencies = [
- "utf8parse",
-]
-
-[[package]]
-name = "anstyle-query"
-version = "1.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "40c48f72fd53cd289104fc64099abca73db4166ad86ea0b4341abe65af83dadc"
-dependencies = [
- "windows-sys 0.61.2",
-]
-
-[[package]]
-name = "anstyle-wincon"
-version = "3.0.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "291e6a250ff86cd4a820112fb8898808a366d8f9f58ce16d1f538353ad55747d"
-dependencies = [
- "anstyle",
- "once_cell_polyfill",
- "windows-sys 0.61.2",
-]
-
 [[package]]
 name = "anyhow"
 version = "1.0.102"
@@ -554,46 +504,12 @@ dependencies = [
  "inout",
 ]
 
-[[package]]
-name = "clap"
-version = "4.6.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b193af5b67834b676abd72466a96c1024e6a6ad978a1f484bd90b85c94041351"
-dependencies = [
- "clap_builder",
-]
-
-[[package]]
-name = "clap_builder"
-version = "4.6.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "714a53001bf66416adb0e2ef5ac857140e7dc3a0c48fb28b2f10762fc4b5069f"
-dependencies = [
- "anstream",
- "anstyle",
- "clap_lex",
- "strsim",
- "terminal_size",
-]
-
-[[package]]
-name = "clap_lex"
-version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c8d4a3bb8b1e0c1050499d1815f5ab16d04f0959b233085fb31653fbfc9d98f9"
-
 [[package]]
 name = "color_quant"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3d7b894f5411737b7867f4827955924d7c254fc9f4d91a6aad6b097804b1018b"
 
-[[package]]
-name = "colorchoice"
-version = "1.0.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d07550c9036bf2ae0c684c4297d503f838287c83c53686d05370d0e139ae570"
-
 [[package]]
 name = "compression-codecs"
 version = "0.4.37"
@@ -677,15 +593,6 @@ dependencies = [
  "cfg-if",
 ]
 
-[[package]]
-name = "crossbeam-channel"
-version = "0.5.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "82b8f8f868b36967f9606790d1903570de9ceaf870a7bf9fbbd3016d636a2cb2"
-dependencies = [
- "crossbeam-utils",
-]
-
 [[package]]
 name = "crossbeam-deque"
 version = "0.8.6"
@@ -816,27 +723,6 @@ dependencies = [
  "cfg-if",
 ]
 
-[[package]]
-name = "env_filter"
-version = "1.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32e90c2accc4b07a8456ea0debdc2e7587bdd890680d71173a15d4ae604f6eef"
-dependencies = [
- "log",
-]
-
-[[package]]
-name = "env_logger"
-version = "0.11.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0621c04f2196ac3f488dd583365b9c09be011a4ab8b9f37248ffcc8f6198b56a"
-dependencies = [
- "anstream",
- "anstyle",
- "env_filter",
- "log",
-]
-
 [[package]]
 name = "equator"
 version = "0.4.2"
@@ -1229,12 +1115,6 @@ dependencies = [
  "weezl",
 ]
 
-[[package]]
-name = "glob"
-version = "0.3.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0cc23270f6e1808e30a928bdc84dea0b9b4136a8bc82338574f23baf47bbd280"
-
 [[package]]
 name = "governor"
 version = "0.6.3"
@@ -1622,7 +1502,6 @@ checksum = "7714e70437a7dc3ac8eb7e6f8df75fd8eb422675fc7678aff7364301092b1017"
 dependencies = [
  "equivalent",
  "hashbrown 0.16.1",
- "rayon",
  "serde",
  "serde_core",
 ]
@@ -1656,12 +1535,6 @@ dependencies = [
  "syn",
 ]
 
-[[package]]
-name = "is_terminal_polyfill"
-version = "1.70.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a6cb138bb79a146c1bd460005623e142ef0181e3d0219cb493e02f7d08a35695"
-
 [[package]]
 name = "itertools"
 version = "0.14.0"
@@ -1795,12 +1668,6 @@ dependencies = [
  "vcpkg",
 ]
 
-[[package]]
-name = "linux-raw-sys"
-version = "0.12.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32a66949e030da00e8c7d4434b251670a91556f4144941d37452769c25d58a53"
-
 [[package]]
 name = "litemap"
 version = "0.8.1"
@@ -2089,12 +1956,6 @@ version = "1.21.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9f7c3e4beb33f85d45ae3e3a1792185706c8e16d043238c593331cc7cd313b50"
 
-[[package]]
-name = "once_cell_polyfill"
-version = "1.70.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
-
 [[package]]
 name = "oxipng"
 version = "9.1.5"
@@ -2102,18 +1963,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "26c613f0f566526a647c7473f6a8556dbce22c91b13485ee4b4ec7ab648e4973"
 dependencies = [
  "bitvec",
- "clap",
- "crossbeam-channel",
- "env_logger",
  "filetime",
- "glob",
  "indexmap",
  "libdeflater",
  "log",
- "rayon",
  "rgb",
  "rustc-hash",
- "zopfli",
 ]
 
 [[package]]
@@ -2607,19 +2462,6 @@ version = "2.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "94300abf3f1ae2e2b8ffb7b58043de3d399c73fa6f4b73826402a5c457614dbe"
 
-[[package]]
-name = "rustix"
-version = "1.1.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6fe4565b9518b83ef4f91bb47ce29620ca828bd32cb7e408f0062e9930ba190"
-dependencies = [
- "bitflags",
- "errno",
- "libc",
- "linux-raw-sys",
- "windows-sys 0.61.2",
-]
-
 [[package]]
 name = "rustversion"
 version = "1.0.22"
@@ -3060,12 +2902,6 @@ dependencies = [
  "unicode-properties",
 ]
 
-[[package]]
-name = "strsim"
-version = "0.11.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
-
 [[package]]
 name = "subtle"
 version = "2.6.1"
@@ -3120,16 +2956,6 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "55937e1799185b12863d447f42597ed69d9928686b8d88a1df17376a097d8369"
 
-[[package]]
-name = "terminal_size"
-version = "0.4.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "230a1b821ccbd75b185820a1f1ff7b14d21da1e442e22c0863ea5f08771a8874"
-dependencies = [
- "rustix",
- "windows-sys 0.61.2",
-]
-
 [[package]]
 name = "thiserror"
 version = "1.0.69"
@@ -3505,12 +3331,6 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b6c140620e7ffbb22c2dee59cafe6084a59b5ffc27a8859a5f0d494b5d52b6be"
 
-[[package]]
-name = "utf8parse"
-version = "0.2.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
-
 [[package]]
 name = "uuid"
 version = "1.23.0"
@@ -4187,18 +4007,6 @@ version = "1.0.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b8848ee67ecc8aedbaf3e4122217aff892639231befc6a1b58d29fff4c2cabaa"
 
-[[package]]
-name = "zopfli"
-version = "0.8.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f05cd8797d63865425ff89b5c4a48804f35ba0ce8d125800027ad6017d2b5249"
-dependencies = [
- "bumpalo",
- "crc32fast",
- "log",
- "simd-adler32",
-]
-
 [[package]]
 name = "zstd"
 version = "0.13.3"

backend/Cargo.toml

@@ -27,7 +27,17 @@ tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 dotenvy = "0.15"
 sysinfo = "0.32"
 image = "0.25"
-oxipng = "9"
+# default-features = false drops "parallel", which is what actually bounds oxipng's memory:
+# with rayon it evaluates row filters concurrently, each trial holding its own full-size
+# buffer, and there is no Options knob to cap that. Without the feature, lib.rs swaps in a
+# sequential shim (oxipng's own supported path) so peak scales with ONE trial, not N.
+# PNG optimisation gets slower; it is a background, best-effort, lossless size saving.
+#
+# "filetime" must be KEPT: without it OutFile::Path { preserve_attrs: true } silently no-ops.
+# Dropping "binary" also removes clap/glob/env_logger — a CLI's dependencies that were being
+# compiled into a server image — and "zopfli", which preset 2 does not use (it selects
+# Deflaters::Libdeflater, which is not feature-gated).
+oxipng = { version = "9", default-features = false, features = ["filetime"] }
 async_zip = { version = "0.0.17", features = ["tokio", "deflate"] }
 include_dir = "0.7"
 infer = "0.15"

backend/migrations/011_ban_hides_and_pin_reset.down.sql

@@ -0,0 +1,25 @@
+DROP TABLE IF EXISTS pin_reset_request;
+
+-- Restore v_feed without the is_banned filter.
+CREATE OR REPLACE VIEW v_feed AS
+SELECT
+    u.id,
+    u.event_id,
+    u.user_id,
+    usr.display_name             AS uploader_name,
+    usr.is_banned,
+    usr.uploads_hidden,
+    u.preview_path,
+    u.thumbnail_path,
+    u.mime_type,
+    u.caption,
+    u.created_at,
+    COUNT(DISTINCT l.user_id)    AS like_count,
+    COUNT(DISTINCT c.id)         AS comment_count
+FROM upload u
+JOIN "user" usr ON u.user_id = usr.id
+LEFT JOIN "like" l  ON l.upload_id = u.id
+LEFT JOIN comment c ON c.upload_id = u.id AND c.deleted_at IS NULL
+WHERE u.deleted_at IS NULL
+  AND usr.uploads_hidden = FALSE
+GROUP BY u.id, usr.display_name, usr.is_banned, usr.uploads_hidden;

backend/migrations/011_ban_hides_and_pin_reset.up.sql

@@ -0,0 +1,39 @@
+-- Ban now ALWAYS hides: exclude banned uploaders from the feed view. Previously ban and
+-- hide were decoupled (a host could ban without hiding), leaving a banned user's photos on
+-- the feed and baked into the export. `find_visible_media` and the export query get the
+-- same `is_banned = FALSE` filter in code.
+CREATE OR REPLACE VIEW v_feed AS
+SELECT
+    u.id,
+    u.event_id,
+    u.user_id,
+    usr.display_name             AS uploader_name,
+    usr.is_banned,
+    usr.uploads_hidden,
+    u.preview_path,
+    u.thumbnail_path,
+    u.mime_type,
+    u.caption,
+    u.created_at,
+    COUNT(DISTINCT l.user_id)    AS like_count,
+    COUNT(DISTINCT c.id)         AS comment_count
+FROM upload u
+JOIN "user" usr ON u.user_id = usr.id
+LEFT JOIN "like" l  ON l.upload_id = u.id
+LEFT JOIN comment c ON c.upload_id = u.id AND c.deleted_at IS NULL
+WHERE u.deleted_at IS NULL
+  AND usr.uploads_hidden = FALSE
+  AND usr.is_banned = FALSE
+GROUP BY u.id, usr.display_name, usr.is_banned, usr.uploads_hidden;
+
+-- pin_reset_request: a guest who forgot their PIN (localStorage was the only copy) can ask
+-- a host to reset it in-app, instead of being permanently orphaned. One pending request per
+-- user; cleared when the host resets the PIN or dismisses it, and cascades if the user/event
+-- is removed.
+CREATE TABLE pin_reset_request (
+    id          UUID        PRIMARY KEY DEFAULT gen_random_uuid(),
+    event_id    UUID        NOT NULL REFERENCES event(id) ON DELETE CASCADE,
+    user_id     UUID        NOT NULL REFERENCES "user"(id) ON DELETE CASCADE,
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    UNIQUE (user_id)
+);

backend/migrations/012_export_release_seq.down.sql

@@ -0,0 +1,2 @@
+ALTER TABLE export_job
+    DROP COLUMN IF EXISTS release_seq;

backend/migrations/012_export_release_seq.up.sql

@@ -0,0 +1,11 @@
+-- H1: export generation guard. A reopen (which clears `export_released_at`) followed by a
+-- re-release could spawn a fresh export worker while a worker from the PRIOR release was
+-- still streaming a now-stale snapshot to `Gallery.zip`. The stale worker's finalize then
+-- re-set `export_*_ready = TRUE` on an archive that predated the reopen — a silent,
+-- permanent data loss (new uploads missing from a "ready" keepsake).
+--
+-- `release_seq` is a per-(event,type) generation counter bumped on every (re)release.
+-- A worker captures the seq it claimed and only finalizes / flips the ready flag while
+-- that seq is still current; a superseded worker discards its output instead.
+ALTER TABLE export_job
+    ADD COLUMN release_seq BIGINT NOT NULL DEFAULT 0;

backend/migrations/013_uploads_hidden_at.down.sql

@@ -0,0 +1,2 @@
+ALTER TABLE "user"
+    DROP COLUMN IF EXISTS uploads_hidden_at;

backend/migrations/013_uploads_hidden_at.up.sql

@@ -0,0 +1,12 @@
+-- Ban-replay on reconnect. A ban is not a soft-delete (it sets `uploads_hidden`/`is_banned`,
+-- never `upload.deleted_at`), and live eviction rode only on the ephemeral `user-hidden` SSE
+-- broadcast — which has no reconnect-replay. So a client (especially the unattended diashow
+-- projector) that missed that broadcast kept cycling the banned user's already-loaded slides.
+--
+-- `uploads_hidden_at` stamps WHEN a user's uploads became hidden, so the reconnect delta can
+-- return the set of users hidden since the client's cursor and the client can evict them.
+ALTER TABLE "user"
+    ADD COLUMN uploads_hidden_at TIMESTAMPTZ;
+
+-- Backfill already-hidden users so a reconnect right after this migration still evicts them.
+UPDATE "user" SET uploads_hidden_at = NOW() WHERE uploads_hidden = TRUE;

backend/migrations/014_export_epoch.down.sql

@@ -0,0 +1,28 @@
+-- Restore the stored ready flags and the per-job counter.
+DROP VIEW IF EXISTS export_current;
+
+ALTER TABLE event ADD COLUMN export_zip_ready  BOOLEAN NOT NULL DEFAULT FALSE;
+ALTER TABLE event ADD COLUMN export_html_ready BOOLEAN NOT NULL DEFAULT FALSE;
+
+-- Re-derive the flags from what the epoch model considers downloadable, so the old code sees
+-- exactly the state it would have written itself.
+UPDATE event e
+   SET export_zip_ready = EXISTS (
+         SELECT 1 FROM export_job j
+          WHERE j.event_id = e.id AND j.type = 'zip'
+            AND j.status = 'done' AND j.epoch = e.export_epoch
+       ),
+       export_html_ready = EXISTS (
+         SELECT 1 FROM export_job j
+          WHERE j.event_id = e.id AND j.type = 'html'
+            AND j.status = 'done' AND j.epoch = e.export_epoch
+       )
+ WHERE e.export_released_at IS NOT NULL;
+
+ALTER TABLE export_job RENAME COLUMN epoch TO release_seq;
+
+-- The old code treats release_seq as a non-negative per-job counter; the -1 retirement sentinel
+-- has no meaning there, so floor it back to 0.
+UPDATE export_job SET release_seq = 0 WHERE release_seq < 0;
+
+ALTER TABLE event DROP COLUMN export_epoch;

backend/migrations/014_export_epoch.up.sql

@@ -0,0 +1,86 @@
+-- Export generation, unified.
+--
+-- ⚠ ROLLBACK RUNBOOK. This is the repo's first DESTRUCTIVE migration (it DROPs two columns). The
+-- previous image will NOT boot against this schema: sqlx runs migrations before serving and errors
+-- with VersionMissing on an unknown version, so you get a crash loop, not a degraded service.
+-- To roll back to the previous release you must run 014_export_epoch.down.sql BY HAND FIRST, then
+-- deploy the old image. The down migration re-derives the old ready flags from the epoch state, so
+-- no keepsake is lost.
+--
+-- Before this migration, "which generation of the keepsake is current?" had no single answer.
+-- It was assembled at runtime from three separately-written pieces of state across two tables:
+--   * event.export_released_at   — a release marker with NO identity (you cannot ask *which* release)
+--   * export_job.release_seq     — a per-row counter, in a different table, bumped in a different statement
+--   * event.export_{zip,html}_ready — a CACHED COPY of the derivation of the other two
+-- Keeping those three in agreement took ~10 hand-written guards, and every guard was a repair of the
+-- same missing invariant. Three consecutive review rounds each found another path that slipped through.
+--
+-- This replaces all of it with ONE authority:
+--
+--   event.export_epoch — a monotonic counter bumped in the SAME UPDATE as any change to
+--                        export_released_at (release and reopen are its only writers).
+--   export_job.epoch   — a COPY of event.export_epoch taken when the job was enqueued.
+--                        NEVER independently incremented.
+--
+-- The single invariant, which replaces the entire proof:
+--
+--   An export is downloadable IFF
+--       event.export_released_at IS NOT NULL
+--   AND export_job.epoch = event.export_epoch
+--   AND export_job.status = 'done'
+--
+-- Readiness is therefore DERIVED, never stored — so it cannot drift, and no worker can set it.
+-- A worker holding a dead epoch is INERT BY CONSTRUCTION: anything it writes is invisible to every
+-- reader, with no guard involved. Losing a race can no longer corrupt state; it can only waste work.
+--
+-- Crucially, epoch equality is checked on the SAME ROW the worker updates (export_job), never via a
+-- cross-table EXISTS. That matters: under READ COMMITTED, when an UPDATE blocks on a row lock and the
+-- blocker commits, Postgres re-evaluates the WHERE against the *updated target row* but answers
+-- subqueries on OTHER tables from the statement's ORIGINAL snapshot. The old cross-row guard
+-- (`EXISTS (SELECT 1 FROM event WHERE ... export_released_at IS NOT NULL)`) was unsound for exactly
+-- that reason — it could admit a claim against an already-reopened event while RETURNING the
+-- post-bump seq. A same-row `epoch = $n` predicate is re-evaluated correctly by EPQ.
+
+ALTER TABLE event ADD COLUMN export_epoch BIGINT NOT NULL DEFAULT 0;
+
+-- A currently-released event's live generation becomes epoch 1.
+UPDATE event SET export_epoch = 1 WHERE export_released_at IS NOT NULL;
+
+-- The per-job counter becomes a plain copy of the event epoch it was enqueued for.
+ALTER TABLE export_job RENAME COLUMN release_seq TO epoch;
+
+-- Carry the OLD notion of "downloadable" across exactly: a job the old model considered ready
+-- (released + done + its ready flag) adopts the event's live epoch. Everything else is retired to
+-- -1, which can never equal a non-negative event.export_epoch, so it is inert forever.
+UPDATE export_job j
+   SET epoch = CASE
+         WHEN e.export_released_at IS NOT NULL
+          AND j.status = 'done'
+          AND ((j.type = 'zip'  AND e.export_zip_ready)
+            OR (j.type = 'html' AND e.export_html_ready))
+         THEN e.export_epoch
+         ELSE -1
+       END
+  FROM event e
+ WHERE e.id = j.event_id;
+
+-- The duplicated derivation. Gone — along with the whole class of bugs where a stale worker
+-- resurrected it, or where it disagreed with the job row it was supposed to summarise.
+ALTER TABLE event DROP COLUMN export_zip_ready;
+ALTER TABLE event DROP COLUMN export_html_ready;
+
+-- The ONE definition of "the current generation". Every reader goes through this, so readiness and
+-- the file path are resolved in a SINGLE read — closing the download-path TOCTOU where the ready
+-- flag was checked in one query and file_path fetched in another (a reopen between the two served a
+-- keepsake that should have 404'd).
+CREATE VIEW export_current AS
+SELECT j.event_id,
+       j.type,
+       j.status,
+       j.progress_pct,
+       j.file_path,
+       j.epoch
+  FROM export_job j
+  JOIN event e ON e.id = j.event_id
+ WHERE e.export_released_at IS NOT NULL   -- implied by the epoch match; kept as an assertion
+   AND j.epoch = e.export_epoch;

backend/migrations/015_raise_upload_rate.down.sql

@@ -0,0 +1,3 @@
+-- Revert the default upload rate to 10/hour for installs still on the raised
+-- default (preserves any explicit admin override at another value).
+UPDATE config SET value = '10' WHERE key = 'upload_rate_per_hour' AND value = '100';

backend/migrations/015_raise_upload_rate.up.sql

@@ -0,0 +1,10 @@
+-- Raise the default per-guest upload rate from 10/hour to 100/hour.
+--
+-- Rationale: guests routinely upload a burst of 10-20 photos at once (phone
+-- multi-select). At the old default of 10/hour a real guest's first burst was
+-- throttled — surfaced by the 2026-07-18 load test. 100/hour comfortably covers
+-- several bursts across an event while still bounding abuse.
+--
+-- Only bump installs still on the old default; an admin who deliberately set a
+-- different value keeps it (migration 005 seeded 10; this UPDATE is scoped to '10').
+UPDATE config SET value = '100' WHERE key = 'upload_rate_per_hour' AND value = '10';

backend/migrations/016_display_derivative.down.sql

@@ -0,0 +1,28 @@
+-- Drop the view (frees the column dependency), remove the column, then restore the
+-- pre-016 view definition (matches migration 011).
+DROP VIEW IF EXISTS v_feed;
+ALTER TABLE upload DROP COLUMN display_path;
+
+CREATE VIEW v_feed AS
+SELECT
+    u.id,
+    u.event_id,
+    u.user_id,
+    usr.display_name             AS uploader_name,
+    usr.is_banned,
+    usr.uploads_hidden,
+    u.preview_path,
+    u.thumbnail_path,
+    u.mime_type,
+    u.caption,
+    u.created_at,
+    COUNT(DISTINCT l.user_id)    AS like_count,
+    COUNT(DISTINCT c.id)         AS comment_count
+FROM upload u
+JOIN "user" usr ON u.user_id = usr.id
+LEFT JOIN "like" l  ON l.upload_id = u.id
+LEFT JOIN comment c ON c.upload_id = u.id AND c.deleted_at IS NULL
+WHERE u.deleted_at IS NULL
+  AND usr.uploads_hidden = FALSE
+  AND usr.is_banned = FALSE
+GROUP BY u.id, usr.display_name, usr.is_banned, usr.uploads_hidden;

backend/migrations/016_display_derivative.up.sql

@@ -0,0 +1,34 @@
+-- Display derivative: a big-screen-quality image (~2048px long edge) for the diashow.
+-- The 800px `preview_path` is sized for phone feeds (data saver); upscaled on a projector
+-- it looks soft. The diashow uses `display_path` instead — bounded in size (safe to decode
+-- on weak kiosk hardware) yet sharp on 1080p/4K. NULL until the compression worker (or the
+-- one-time backfill) generates it; consumers fall back to the original when absent.
+ALTER TABLE upload ADD COLUMN display_path TEXT;
+
+-- Recreate (not CREATE OR REPLACE, which only allows appending columns at the end) so the
+-- new column can sit alongside preview_path/thumbnail_path.
+DROP VIEW IF EXISTS v_feed;
+CREATE VIEW v_feed AS
+SELECT
+    u.id,
+    u.event_id,
+    u.user_id,
+    usr.display_name             AS uploader_name,
+    usr.is_banned,
+    usr.uploads_hidden,
+    u.preview_path,
+    u.thumbnail_path,
+    u.display_path,
+    u.mime_type,
+    u.caption,
+    u.created_at,
+    COUNT(DISTINCT l.user_id)    AS like_count,
+    COUNT(DISTINCT c.id)         AS comment_count
+FROM upload u
+JOIN "user" usr ON u.user_id = usr.id
+LEFT JOIN "like" l  ON l.upload_id = u.id
+LEFT JOIN comment c ON c.upload_id = u.id AND c.deleted_at IS NULL
+WHERE u.deleted_at IS NULL
+  AND usr.uploads_hidden = FALSE
+  AND usr.is_banned = FALSE
+GROUP BY u.id, usr.display_name, usr.is_banned, usr.uploads_hidden;

backend/migrations/017_join_ip_rate.down.sql

@@ -0,0 +1 @@
+DELETE FROM config WHERE key IN ('join_ip_rate_per_min', 'admin_login_rate_enabled');

backend/migrations/017_join_ip_rate.up.sql

@@ -0,0 +1,18 @@
+-- Per-IP flood ceiling for /join, and the `admin_login_rate_enabled` toggle that
+-- every prior migration forgot to seed.
+--
+-- Rationale: /join was throttled at 5 requests per 60s keyed on the client IP. At a
+-- venue every guest is behind one NAT, so the whole party shared a single bucket —
+-- 12 guests scanning the QR code within a few seconds meant 5 got in and 7 were
+-- turned away. The handler now keys the real anti-spam bucket per (ip, name), the
+-- same shape as `recover:{ip}:{name}`, and keeps only a loose per-IP ceiling to bound
+-- raw volume. 60/min comfortably covers a whole wedding arriving at once while still
+-- capping a flood from a single source.
+--
+-- `admin_login_rate_enabled` is read by auth::handlers::admin_login with a code
+-- default of `true`, but no migration ever inserted it, so it was invisible to the
+-- admin config UI and to the e2e reseed. Seed it explicitly.
+INSERT INTO config (key, value) VALUES
+    ('join_ip_rate_per_min',     '60'),
+    ('admin_login_rate_enabled', 'true')
+ON CONFLICT (key) DO NOTHING;

backend/migrations/018_derivatives_rev.down.sql

@@ -0,0 +1,2 @@
+DROP INDEX IF EXISTS idx_upload_derivatives_rev;
+ALTER TABLE upload DROP COLUMN IF EXISTS derivatives_rev;

backend/migrations/018_derivatives_rev.up.sql

@@ -0,0 +1,18 @@
+-- Track which revision of the derivative pipeline produced an upload's preview/display.
+--
+-- Rev 1 applies the EXIF orientation tag. Everything generated before it decoded the raw
+-- sensor pixels and re-encoded to JPEG (which writes no EXIF), so every portrait phone photo
+-- was stored sideways in the feed preview, the diashow display and the keepsake — while the
+-- untouched original still rendered upright.
+--
+-- Existing rows default to 0 so the startup backfill can find and re-generate them exactly
+-- once; bump the constant in services/compression.rs if the pipeline ever changes again.
+ALTER TABLE upload ADD COLUMN IF NOT EXISTS derivatives_rev SMALLINT NOT NULL DEFAULT 0;
+
+-- Only image derivatives are affected — video thumbnails are extracted by ffmpeg, which
+-- already honours the rotation matrix. Mark them current so the backfill skips them.
+UPDATE upload SET derivatives_rev = 1 WHERE mime_type NOT LIKE 'image/%';
+
+CREATE INDEX IF NOT EXISTS idx_upload_derivatives_rev
+    ON upload (derivatives_rev)
+    WHERE deleted_at IS NULL;

backend/migrations/019_recover_ip_rate.down.sql

@@ -0,0 +1 @@
+DELETE FROM config WHERE key = 'recover_ip_rate_per_min';

backend/migrations/019_recover_ip_rate.up.sql

@@ -0,0 +1,19 @@
+-- Per-IP flood ceiling for /recover, mirroring the one migration 017 added for /join.
+--
+-- Rationale: /recover is keyed `recover:{ip}:{name}` at 5 per 15 minutes. That is the
+-- right shape for its actual job — stopping someone who knows a display name (they are
+-- visible on the feed) from burning the victim's 3-strike PIN counter and locking them
+-- out repeatedly. But the name is attacker-chosen, so cycling names mints a fresh bucket
+-- every time and the per-IP cost is unbounded.
+--
+-- Behind that limiter sits a cost-12 bcrypt verify, including an UNCONDITIONAL throwaway
+-- verify for names that don't exist — deliberately, to close a timing oracle. So an
+-- unknown name is the cheapest possible way to make the server do ~200ms of hashing.
+-- Without a ceiling, one client can saturate the box's CPU with a name generator.
+--
+-- 30/min is far above any real recovery attempt (a guest tries their PIN a handful of
+-- times) while capping a name-cycling flood. The per-(ip, name) bucket is unchanged and
+-- remains the anti-guessing control.
+INSERT INTO config (key, value) VALUES
+    ('recover_ip_rate_per_min', '30')
+ON CONFLICT (key) DO NOTHING;

backend/migrations/020_social_rate.down.sql

@@ -0,0 +1 @@
+DELETE FROM config WHERE key IN ('social_rate_per_min', 'social_rate_enabled');

backend/migrations/020_social_rate.up.sql

@@ -0,0 +1,16 @@
+-- Per-user rate limit for social writes (likes, comments, comment deletions).
+--
+-- These were the only writes in the app with no limit at all. Every other mutating
+-- path -- upload, join, recover, export, admin login -- carries one; social.rs
+-- carried none, so the coverage was asymmetric rather than deliberately open.
+--
+-- Severity is genuinely low for an invited-guest event, and the amplification worry
+-- turned out to be contained: a like fans an SSE broadcast to ~100 clients, but the
+-- export regeneration it could otherwise trigger is debounced (REGEN_DEBOUNCE 20s)
+-- and superseded workers are inert. So this closes the gap for symmetry, not urgency,
+-- and the ceiling is set high enough that no real guest will ever meet it -- a
+-- double-tapping enthusiast at a wedding is not the thing being defended against.
+INSERT INTO config (key, value) VALUES
+    ('social_rate_per_min',  '120'),
+    ('social_rate_enabled',  'true')
+ON CONFLICT (key) DO NOTHING;

backend/migrations/021_derivative_attempts.down.sql

@@ -0,0 +1,3 @@
+DROP INDEX IF EXISTS idx_upload_derivative_backfill;
+ALTER TABLE upload DROP COLUMN IF EXISTS derivative_last_error;
+ALTER TABLE upload DROP COLUMN IF EXISTS derivative_attempts;

backend/migrations/021_derivative_attempts.up.sql

@@ -0,0 +1,23 @@
+-- Bound how many times a permanently-failing upload can be re-processed.
+--
+-- Without this, one poisoned row is an outage. The upload row is committed BEFORE compression
+-- starts, `derivatives_rev` defaults to 0, and `set_derivatives_rev` only runs on success — so
+-- a row whose processing kills the container survives at rev 0, the unconditional startup
+-- backfill re-selects it on the next boot, and `restart: unless-stopped` turns that into an
+-- infinite kill loop. Every restart also drops every SSE stream and truncates every in-flight
+-- upload. That was reachable via a single large PNG (see services/compression.rs), but the
+-- shape is general: any input that can kill or hang the worker repeats forever.
+--
+-- The counter is incremented WRITE-AHEAD, before the work is attempted, because the failure
+-- mode being defended against is a SIGKILL — no error is returned, no handler runs, no Drop
+-- fires. A counter bumped in an error path increments zero times per crash and changes nothing.
+ALTER TABLE upload ADD COLUMN IF NOT EXISTS derivative_attempts SMALLINT NOT NULL DEFAULT 0;
+
+-- Last failure text, so a row that has given up can be diagnosed without reproducing it.
+-- Nothing reads this in code; it exists for the operator.
+ALTER TABLE upload ADD COLUMN IF NOT EXISTS derivative_last_error TEXT;
+
+-- Serves the backfill selection, which now filters on both columns.
+CREATE INDEX IF NOT EXISTS idx_upload_derivative_backfill
+    ON upload (derivatives_rev, derivative_attempts)
+    WHERE deleted_at IS NULL;

backend/migrations/022_feed_scalar_counts.down.sql

@@ -0,0 +1,26 @@
+-- Restore the 016 definition verbatim.
+DROP VIEW IF EXISTS v_feed;
+CREATE VIEW v_feed AS
+SELECT
+    u.id,
+    u.event_id,
+    u.user_id,
+    usr.display_name             AS uploader_name,
+    usr.is_banned,
+    usr.uploads_hidden,
+    u.preview_path,
+    u.thumbnail_path,
+    u.display_path,
+    u.mime_type,
+    u.caption,
+    u.created_at,
+    COUNT(DISTINCT l.user_id)    AS like_count,
+    COUNT(DISTINCT c.id)         AS comment_count
+FROM upload u
+JOIN "user" usr ON u.user_id = usr.id
+LEFT JOIN "like" l  ON l.upload_id = u.id
+LEFT JOIN comment c ON c.upload_id = u.id AND c.deleted_at IS NULL
+WHERE u.deleted_at IS NULL
+  AND usr.uploads_hidden = FALSE
+  AND usr.is_banned = FALSE
+GROUP BY u.id, usr.display_name, usr.is_banned, usr.uploads_hidden;

backend/migrations/022_feed_scalar_counts.up.sql

@@ -0,0 +1,55 @@
+-- Make a feed page cost a page, not the whole event.
+--
+-- The previous definition (016) computed like_count/comment_count with LEFT JOINs and a
+-- GROUP BY. Postgres CAN push the `event_id = $1` qual and the keyset predicate through the
+-- view — verified with EXPLAIN, it uses idx_upload_event_created_id — but it CANNOT push
+-- ORDER BY ... LIMIT across a GroupAggregate. So every feed request aggregated every upload in
+-- the event (times its likes and comments) and only then sorted and took 21 rows. The cost
+-- grew with the event, not with the page, and page 1 — the most expensive one — is exactly
+-- what refreshFeedInPlace refetches on every completed upload, from every open feed in the
+-- venue.
+--
+-- Correlated scalar subqueries move the counts ABOVE the Limit in the plan: they are evaluated
+-- once per returned row, so 21 index lookups instead of a full aggregation.
+--
+-- The rewrite is EXACTLY equivalent, not merely close:
+--   * "like" is keyed (upload_id, user_id), so COUNT(DISTINCT l.user_id) == count(*).
+--   * comment.id is the primary key, so COUNT(DISTINCT c.id) == count(*).
+--   * one row per upload either way — the GROUP BY was on u.id.
+-- Column names, order and types are unchanged (count(*) and COUNT(DISTINCT ...) are both
+-- bigint), so no Rust code changes.
+--
+-- No new index needed: idx_like_upload plus the (upload_id, user_id) PK serve the like
+-- subquery, and idx_comment_upload ... WHERE deleted_at IS NULL matches the comment
+-- subquery's predicate exactly.
+--
+-- One thing a future editor needs to know: the hashtag-filtered feed joins upload_hashtag
+-- against this view. That was safe before only because the GROUP BY collapsed the join
+-- fan-out; it is safe now because the view is one row per upload and upload_hashtag is keyed
+-- (upload_id, hashtag_id) with a single tag filtered. Adding a second tag filter would need
+-- fresh thought.
+
+-- Not CASCADE: if something ever comes to depend on this view, the migration should fail
+-- loudly rather than silently drop it.
+DROP VIEW IF EXISTS v_feed;
+CREATE VIEW v_feed AS
+SELECT
+    u.id,
+    u.event_id,
+    u.user_id,
+    usr.display_name AS uploader_name,
+    usr.is_banned,
+    usr.uploads_hidden,
+    u.preview_path,
+    u.thumbnail_path,
+    u.display_path,
+    u.mime_type,
+    u.caption,
+    u.created_at,
+    (SELECT count(*) FROM "like" l WHERE l.upload_id = u.id)                           AS like_count,
+    (SELECT count(*) FROM comment c WHERE c.upload_id = u.id AND c.deleted_at IS NULL) AS comment_count
+FROM upload u
+JOIN "user" usr ON u.user_id = usr.id
+WHERE u.deleted_at IS NULL
+  AND usr.uploads_hidden = FALSE
+  AND usr.is_banned = FALSE;

backend/migrations/023_reserved_names_and_pin_decay.down.sql

@@ -0,0 +1,11 @@
+-- NOTE: the reserved-name rename in the up migration is NOT reversible. The original names
+-- are not recorded anywhere, and reversing it would in any case re-create the state that
+-- bricked admin login. Rolling back the schema does not roll back that data change.
+DELETE FROM config WHERE key IN (
+    'recover_name_rate_per_15min',
+    'pin_reset_ip_rate_per_min',
+    'upload_edit_rate_per_min',
+    'upload_edit_rate_enabled'
+);
+
+ALTER TABLE "user" DROP COLUMN IF EXISTS last_failed_pin_at;

backend/migrations/023_reserved_names_and_pin_decay.up.sql

@@ -0,0 +1,48 @@
+-- Two independent auth defects that share a migration because they share a table.
+
+-- 1. RESERVED NAMES — free any guest squatting on a name the admin path used to depend on.
+--
+-- Migration 007 made display_name unique per event case-insensitively, and `join` had no
+-- reserved-name guard. So any guest could join as "admin"/"Admin"/"ADMIN" before the operator's
+-- first admin login; admin_login then looked its user up BY NAME, missed (wrong role), fell
+-- through to creating "Admin", violated that unique index, and returned a 500 — permanently,
+-- with no in-app recovery. Moderation, config and gallery release all gone, fixed only by SQL.
+--
+-- The real fix is in code (look the admin up by role, never by name — see auth/handlers.rs).
+-- This clears the state an already-deployed database may be carrying.
+--
+-- RENAMED, NEVER DELETED: the guest keeps their uploads, their PIN and their session. Only
+-- non-admin rows are touched — a real admin row named "Admin" is the expected state.
+UPDATE "user" u
+   SET display_name = u.display_name || ' (' || left(u.id::text, 8) || ')'
+ WHERE u.role <> 'admin'
+   AND lower(u.display_name) IN ('admin', 'administrator', 'host', 'eventsnap');
+
+-- 2. PIN LOCKOUT DECAY.
+--
+-- failed_pin_attempts only ever cleared on a successful recovery or after a lockout expired, so
+-- honest typos accumulated across days: a guest who fat-fingered their PIN twice last night
+-- arrives today already two-thirds of the way to being locked out. With the threshold now
+-- raised (see below) a decay window is what keeps that raise safe rather than merely lenient.
+ALTER TABLE "user" ADD COLUMN IF NOT EXISTS last_failed_pin_at TIMESTAMPTZ;
+
+-- Rate-limit knobs introduced with this release.
+--
+-- recover_name_rate_per_15min (4, was a hardcoded 5): the per-(IP, name) ceiling. It MUST stay
+-- below the account-lock threshold, which is the whole defect — at 5-per-IP against a 3-strike
+-- lock, three requests from one IP locked any guest whose name is visible on the feed, every 15
+-- minutes, forever. The lock threshold moves to 12 in code, so locking a victim now needs at
+-- least three distinct sources while an honest guest never comes close.
+--
+-- pin_reset_ip_rate_per_min (30): /recover/request was the one unauthenticated endpoint with no
+-- per-IP ceiling at all — /join got one in 017 and /recover in 019, and this third one was
+-- simply missed. Its per-name key is attacker-chosen, so cycling names minted a fresh bucket
+-- every time and the per-IP cost was unbounded.
+--
+-- upload_edit_rate_per_min (30): PATCH /upload/{id} had no rate limit of any kind.
+INSERT INTO config (key, value) VALUES
+    ('recover_name_rate_per_15min', '4'),
+    ('pin_reset_ip_rate_per_min',   '30'),
+    ('upload_edit_rate_per_min',    '30'),
+    ('upload_edit_rate_enabled',    'true')
+ON CONFLICT (key) DO NOTHING;

backend/scripts/rehearse-014.sh

@@ -0,0 +1,195 @@
+#!/usr/bin/env bash
+#
+# Dress rehearsal for migration 014 (export_epoch) — the repo's first DESTRUCTIVE migration.
+#
+# 014 DROPs event.export_zip_ready / export_html_ready and rewrites export_job.release_seq into an
+# epoch. The dangerous part is not the DDL, it's the BACKFILL: it has to carry the old notion of
+# "downloadable" across exactly. Get it wrong and a released event's keepsake silently 404s for
+# every guest, on a dataset you cannot re-create.
+#
+# This script proves the backfill preserves downloadability, against a scratch copy of a REAL dump:
+#
+#   ./rehearse-014.sh /path/to/prod-dump.sql     # rehearse against production data
+#   ./rehearse-014.sh                            # synthetic: build a pre-014 DB covering every case
+#
+# It asserts:
+#   1. up:   {(event,type) downloadable BEFORE} == {(event,type) downloadable AFTER}
+#   2. down: the old ready flags come back identical  (so a rollback is actually a rollback)
+#   3. up again: still identical                      (so a roll-forward after a rollback is safe)
+#
+# It NEVER touches your real database. Everything runs in a throwaway container.
+#
+# NOTE ON ROLLBACK (see the runbook header in 014_export_epoch.up.sql): sqlx runs migrations before
+# serving and errors with VersionMissing on an unknown version, so the PREVIOUS image will not boot
+# against the 014 schema — it crash-loops. Rolling back means running 014_export_epoch.down.sql BY
+# HAND FIRST, then deploying the old image. Assertion 2 is what makes that safe. Rehearse it before
+# you need it, not while the party is happening.
+
+set -euo pipefail
+
+DUMP="${1:-}"
+MIG_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/../migrations" && pwd)"
+CONTAINER="eventsnap-rehearse-014"
+PGPASSWORD="rehearse"
+DB="eventsnap_rehearsal"
+
+cleanup() { docker rm -f "$CONTAINER" > /dev/null 2>&1 || true; }
+trap cleanup EXIT
+cleanup
+
+echo "▸ Starting a throwaway postgres:16 (nothing here touches your real DB)…"
+docker run --rm -d --name "$CONTAINER" \
+  -e POSTGRES_PASSWORD="$PGPASSWORD" -e POSTGRES_DB="$DB" \
+  postgres:16-alpine > /dev/null
+
+psql() { docker exec -i -e PGPASSWORD="$PGPASSWORD" "$CONTAINER" psql -U postgres -d "$DB" -v ON_ERROR_STOP=1 "$@"; }
+
+for _ in $(seq 1 30); do
+  if docker exec "$CONTAINER" pg_isready -U postgres > /dev/null 2>&1; then break; fi
+  sleep 1
+done
+
+if [[ -n "$DUMP" ]]; then
+  echo "▸ Restoring $DUMP …"
+  psql -q < "$DUMP"
+else
+  echo "▸ No dump given — building a synthetic pre-014 DB (migrations 001→013)…"
+  for f in "$MIG_DIR"/0[0-1][0-9]_*.up.sql; do
+    [[ "$(basename "$f")" == 014_* ]] && continue
+    psql -q < "$f"
+  done
+
+  # Every state the backfill has to classify. If 014 mishandles ANY of these, assertion 1 fails.
+  # Every state the backfill has to classify. export_job is UNIQUE (event_id, type), so each event
+  # has at most one job per type — the cases are distinguished by event, not by piling up rows.
+  #   A: released, both flags, both done  → both stay downloadable
+  #   B: released, ZIP flag only          → ZIP downloadable, HTML not (a half-built keepsake)
+  #   C: released, jobs done, NO flags    → NOT downloadable (a superseded worker's finished job:
+  #                                          the exact state the old ready-flag model used to leak)
+  #   D: never released, jobs done        → NOT downloadable (reopened, or built before release)
+  #   E: released, ZIP flag set but the job is FAILED/RUNNING → NOT downloadable (flag/job disagree,
+  #                                          which the old two-source model made representable at all)
+  echo "▸ Seeding: released+both, zip-only, done-but-stale, unreleased, flag/job-disagreement…"
+  psql -q <<'SQL'
+INSERT INTO event (id, slug, name, export_released_at, export_zip_ready, export_html_ready) VALUES
+  ('aaaaaaaa-0000-0000-0000-000000000001','ev-a','A', now(), TRUE,  TRUE),
+  ('aaaaaaaa-0000-0000-0000-000000000002','ev-b','B', now(), TRUE,  FALSE),
+  ('aaaaaaaa-0000-0000-0000-000000000003','ev-c','C', now(), FALSE, FALSE),
+  ('aaaaaaaa-0000-0000-0000-000000000004','ev-d','D', NULL,  FALSE, FALSE),
+  ('aaaaaaaa-0000-0000-0000-000000000005','ev-e','E', now(), TRUE,  TRUE);
+
+INSERT INTO export_job (event_id, type, status, progress_pct, file_path, release_seq)
+SELECT e.id, t::export_type, 'done'::export_status, 100, '/x/' || e.slug || '.' || t, 0
+  FROM event e CROSS JOIN (VALUES ('zip'),('html')) AS v(t);
+
+-- E: the flags claim ready, the jobs say otherwise. Old model required BOTH, so neither is
+-- downloadable — the migration must not "trust the flag" and resurrect them.
+UPDATE export_job SET status = 'failed',  file_path = NULL, progress_pct = 40
+ WHERE event_id = 'aaaaaaaa-0000-0000-0000-000000000005' AND type = 'zip';
+UPDATE export_job SET status = 'running', file_path = NULL, progress_pct = 70
+ WHERE event_id = 'aaaaaaaa-0000-0000-0000-000000000005' AND type = 'html';
+SQL
+fi
+
+echo "▸ Snapshotting what is downloadable under the OLD model…"
+psql -q <<'SQL'
+CREATE TABLE _rehearsal_before AS
+SELECT j.event_id, j.type
+  FROM export_job j JOIN event e ON e.id = j.event_id
+ WHERE e.export_released_at IS NOT NULL
+   AND j.status = 'done'
+   AND ((j.type = 'zip' AND e.export_zip_ready) OR (j.type = 'html' AND e.export_html_ready));
+
+-- For assertion 2: the exact flags a rollback has to reproduce.
+CREATE TABLE _rehearsal_flags AS
+SELECT id, export_zip_ready, export_html_ready FROM event;
+SQL
+
+before=$(psql -tAc "SELECT count(*) FROM _rehearsal_before")
+echo "  → $before (event,type) pair(s) downloadable before."
+
+# The assertion. A symmetric difference of zero means the backfill carried the old notion of
+# "downloadable" across EXACTLY: nothing gained (a stale keepsake resurrected), nothing lost (a
+# guest's keepsake silently 404s).
+assert_up_preserves() {
+  local label="$1" diff
+  diff=$(psql -tAc "
+    SELECT count(*) FROM (
+      (SELECT event_id, type FROM _rehearsal_before
+        EXCEPT SELECT event_id, type FROM export_current WHERE status = 'done')
+      UNION ALL
+      (SELECT event_id, type FROM export_current WHERE status = 'done'
+        EXCEPT SELECT event_id, type FROM _rehearsal_before)
+    ) d")
+  if [[ "$diff" != "0" ]]; then
+    echo "✗ FAIL ($label): $diff (event,type) pair(s) changed downloadability across the migration."
+    psql -c "
+      (SELECT 'LOST — guests can no longer download this' AS problem, event_id, type FROM _rehearsal_before
+        EXCEPT ALL SELECT 'LOST — guests can no longer download this', event_id, type FROM export_current WHERE status='done')
+      UNION ALL
+      (SELECT 'GAINED — a stale keepsake became downloadable', event_id, type FROM export_current WHERE status='done'
+        EXCEPT ALL SELECT 'GAINED — a stale keepsake became downloadable', event_id, type FROM _rehearsal_before)"
+    exit 1
+  fi
+  echo "✓ $label: downloadability preserved exactly ($before pair(s))."
+}
+
+echo "▸ Applying 014 (up)…"
+psql -q < "$MIG_DIR/014_export_epoch.up.sql"
+assert_up_preserves "up"
+
+echo "▸ Applying 014 (down) — the rollback path…"
+psql -q < "$MIG_DIR/014_export_epoch.down.sql"
+
+# The down migration is an inverse UP TO DRIFT, not a bit-exact inverse — deliberately.
+#
+# The old model let a ready flag disagree with its job row (flag TRUE over a running/failed job):
+# the flag was a CACHED copy of a derivation, and keeping a cache in agreement with its source
+# across concurrent workers is precisely what it kept failing at. The down migration re-derives the
+# flags from the epoch state, so such a pair comes back FALSE. That HEALS the drift rather than
+# faithfully restoring corruption, and it costs nothing: a flag over a non-done job had no file to
+# serve (file_path is NULL until the worker finishes), so the old code 404'd on it anyway.
+#
+# What a rollback must NOT do is drop a flag for a keepsake that was genuinely downloadable
+# (flag set AND the job actually done). That is the assertion.
+lost=$(psql -tAc "
+  SELECT count(*) FROM _rehearsal_before b
+   WHERE NOT EXISTS (
+     SELECT 1 FROM event e
+      WHERE e.id = b.event_id
+        AND ((b.type = 'zip' AND e.export_zip_ready) OR (b.type = 'html' AND e.export_html_ready)))")
+if [[ "$lost" != "0" ]]; then
+  echo "✗ FAIL (down): $lost downloadable keepsake(s) lost their ready flag — the rollback is LOSSY."
+  psql -c "
+    SELECT b.event_id, b.type, 'was downloadable, flag not restored' AS problem
+      FROM _rehearsal_before b
+     WHERE NOT EXISTS (
+       SELECT 1 FROM event e
+        WHERE e.id = b.event_id
+          AND ((b.type = 'zip' AND e.export_zip_ready) OR (b.type = 'html' AND e.export_html_ready)))"
+  exit 1
+fi
+echo "✓ down: every downloadable keepsake kept its flag — the old image sees a working state."
+
+healed=$(psql -tAc "
+  SELECT count(*) FROM event e JOIN _rehearsal_flags f ON f.id = e.id
+   WHERE (e.export_zip_ready, e.export_html_ready) IS DISTINCT FROM (f.export_zip_ready, f.export_html_ready)")
+if [[ "$healed" != "0" ]]; then
+  echo "  ℹ $healed event(s) came back with a CLEARED flag that had drifted from its job row."
+  echo "    Not a loss — those had no file to serve. The rollback normalises them; the old code"
+  echo "    will rebuild on the next release. Listing them so the behaviour is not a surprise:"
+  psql -c "SELECT e.id, f.export_zip_ready AS was_zip, e.export_zip_ready AS now_zip,
+                  f.export_html_ready AS was_html, e.export_html_ready AS now_html
+             FROM event e JOIN _rehearsal_flags f ON f.id = e.id
+            WHERE (e.export_zip_ready, e.export_html_ready)
+                  IS DISTINCT FROM (f.export_zip_ready, f.export_html_ready)"
+fi
+
+echo "▸ Re-applying 014 (up) — roll forward after a rollback…"
+psql -q < "$MIG_DIR/014_export_epoch.up.sql"
+assert_up_preserves "up (after rollback)"
+
+echo
+echo "✓ Rehearsal passed. 014 is safe to deploy against this dataset."
+[[ -z "$DUMP" ]] && echo "  (synthetic data — re-run with a real pg_dump before you deploy for real)"
+exit 0

backend/src/auth/handlers.rs

@@ -1,11 +1,12 @@
 use std::time::Duration;
 
-use axum::extract::State;
-use axum::http::{HeaderMap, StatusCode};
 use axum::Json;
+use axum::extract::{ConnectInfo, State};
+use axum::http::{HeaderMap, StatusCode};
 use chrono::Utc;
 use rand::Rng;
 use serde::{Deserialize, Serialize};
+use std::net::SocketAddr;
 use uuid::Uuid;
 
 use crate::auth::jwt;
@@ -18,6 +19,45 @@ use crate::services::config;
 use crate::services::rate_limiter::client_ip;
 use crate::state::AppState;
 
+/// Names a guest may not take.
+///
+/// Defence in depth only. The real fix for the admin-lockout defect is that `admin_login` now
+/// resolves its user by ROLE rather than by name (see `User::find_admin_for_event`), which is
+/// why homoglyph and zero-width bypasses of this list are not a concern: the name is no longer
+/// load-bearing for anything. What this buys is that a guest cannot impersonate the host in the
+/// feed's byline, and that "Admin" stays available for the admin row.
+const RESERVED_DISPLAY_NAMES: &[&str] = &["admin", "administrator", "host", "eventsnap"];
+
+fn is_reserved_display_name(name: &str) -> bool {
+    let name = name.trim().to_lowercase();
+    RESERVED_DISPLAY_NAMES.contains(&name.as_str())
+}
+
+/// Trim and bounds-check a display name.
+///
+/// Shared by `join`, `recover` and `request_pin_reset` so the length check happens BEFORE the
+/// name is used to build a rate-limiter key. It was inline in `join` only, so on the other two
+/// endpoints `format!("...:{ip}:{name_key}")` allocated from an unbounded, attacker-chosen
+/// string and stored it in a HashMap pruned once an hour with a 24 h ceiling — turning the
+/// limiter itself into the memory-exhaustion primitive it exists to prevent.
+fn validate_display_name(raw: &str) -> Result<&str, AppError> {
+    let name = raw.trim();
+    let chars = name.chars().count();
+    if chars == 0 || chars > 50 {
+        return Err(AppError::BadRequest(
+            "Name muss zwischen 1 und 50 Zeichen lang sein.".into(),
+        ));
+    }
+    // Postgres rejects 0x00 in TEXT columns with a 500. Catch it here so callers see a clean
+    // 400 instead of an internal error.
+    if name.contains('\0') {
+        return Err(AppError::BadRequest(
+            "Name enthält ungültige Zeichen.".into(),
+        ));
+    }
+    Ok(name)
+}
+
 #[derive(Deserialize)]
 pub struct JoinRequest {
     pub display_name: String,
@@ -33,34 +73,58 @@ pub struct JoinResponse {
 
 pub async fn join(
     State(state): State<AppState>,
+    ConnectInfo(peer): ConnectInfo<SocketAddr>,
     headers: HeaderMap,
     Json(body): Json<JoinRequest>,
 ) -> Result<(StatusCode, Json<JoinResponse>), AppError> {
-    let ip = client_ip(&headers, "unknown");
-    let rate_limits_on = config::get_bool(&state.pool, "rate_limits_enabled", true).await;
-    let join_rate_on = config::get_bool(&state.pool, "join_rate_enabled", true).await;
-    if rate_limits_on && join_rate_on
-        && !state.rate_limiter.check(format!("join:{ip}"), 5, Duration::from_secs(60))
-    {
-        return Err(AppError::TooManyRequests(
-            "Zu viele Anfragen. Bitte warte kurz und versuche es erneut.".into(),
-            None,
-        ));
+    let ip = client_ip(&headers, &peer.ip().to_string());
+    let rate_limits_on = config::get_bool(&state.config_cache, "rate_limits_enabled", true).await;
+    let join_rate_on = config::get_bool(&state.config_cache, "join_rate_enabled", true).await;
+
+    // Coarse per-IP flood ceiling. `/join` is pre-auth so there is no user to key on, and
+    // at a venue EVERY guest arrives from one public IP — a tight per-IP bucket meant the
+    // 6th person through the door was turned away by the 5 ahead of them. So the per-IP
+    // limit here only bounds raw volume; the real anti-spam bucket is per-name below.
+    // Cheap enough to run before validation, which keeps a flood of malformed bodies from
+    // being free.
+    if rate_limits_on && join_rate_on {
+        let ip_ceiling = config::get_usize(&state.config_cache, "join_ip_rate_per_min", 60).await;
+        if let Err(retry_after_secs) = state.rate_limiter.check_with_retry(
+            format!("join_ip:{ip}"),
+            ip_ceiling,
+            Duration::from_secs(60),
+        ) {
+            return Err(AppError::TooManyRequests(
+                "Zu viele Anfragen. Bitte warte kurz und versuche es erneut.".into(),
+                Some(retry_after_secs),
+            ));
+        }
     }
 
-    let display_name = body.display_name.trim();
-    let name_chars = display_name.chars().count();
-    if name_chars == 0 || name_chars > 50 {
-        return Err(AppError::BadRequest(
-            "Name muss zwischen 1 und 50 Zeichen lang sein.".into(),
-        ));
+    let display_name = validate_display_name(&body.display_name)?;
+    if is_reserved_display_name(display_name) {
+        // 409, matching the name-taken response below, so the frontend's existing handling
+        // works unchanged. See RESERVED_DISPLAY_NAMES for why this exists.
+        return Err(AppError::Conflict(format!(
+            "Der Name \"{display_name}\" ist reserviert. Bitte wähle einen anderen."
+        )));
     }
-    // Postgres rejects 0x00 in TEXT columns with a 500. Catch it here so callers
-    // see a clean 400 instead of an internal error.
-    if display_name.contains('\0') {
-        return Err(AppError::BadRequest(
-            "Name enthält ungültige Zeichen.".into(),
-        ));
+
+    // Per-guest bucket, keyed like the `recover:{ip}:{name}` limiter below. This carries
+    // the original 5/60s anti-spam intent, but one guest retrying can no longer consume
+    // the allowance of everyone else sharing the venue's NAT.
+    if rate_limits_on && join_rate_on {
+        let name_key = display_name.to_lowercase();
+        if let Err(retry_after_secs) = state.rate_limiter.check_with_retry(
+            format!("join:{ip}:{name_key}"),
+            5,
+            Duration::from_secs(60),
+        ) {
+            return Err(AppError::TooManyRequests(
+                "Zu viele Anfragen. Bitte warte kurz und versuche es erneut.".into(),
+                Some(retry_after_secs),
+            ));
+        }
     }
 
     let event = Event::find_or_create(
@@ -80,10 +144,21 @@ pub async fn join(
 
     // Generate a 4-digit PIN
     let pin: String = format!("{:04}", rand::rng().random_range(0..10000u32));
-    let pin_hash =
-        bcrypt::hash(&pin, 12).map_err(|e| AppError::Internal(anyhow::anyhow!(e)))?;
+    let pin_hash = hash_password(pin.clone(), 12).await?;
 
-    let user = User::create(&state.pool, event.id, display_name, &pin_hash).await?;
+    // The pre-check above is racy: two simultaneous joins with the same name can both
+    // pass it, and the DB's unique index then rejects the loser. Map that unique
+    // violation to the same clean 409 the pre-check returns, not a generic 500.
+    let user = match User::create(&state.pool, event.id, display_name, &pin_hash).await {
+        Ok(u) => u,
+        Err(sqlx::Error::Database(db)) if db.is_unique_violation() => {
+            return Err(AppError::Conflict(format!(
+                "Der Name \"{}\" ist bereits vergeben.",
+                display_name
+            )));
+        }
+        Err(e) => return Err(e.into()),
+    };
 
     let token = jwt::create_token(
         user.id,
@@ -109,6 +184,28 @@ pub async fn join(
     ))
 }
 
+/// Default for `recover_name_rate_per_15min` — wrong PINs allowed per (IP, name) per 15 min.
+/// Mirrors migration 023; kept here so the invariant below can be asserted in a test.
+const RECOVER_NAME_CEILING_DEFAULT: usize = 4;
+
+/// Wrong PINs, from ALL sources, before the ACCOUNT itself is locked for 15 minutes.
+///
+/// This was 3, which sat BELOW the per-(IP, name) ceiling of 5 — and that ordering, not the
+/// number, was the defect. Display names are public on the feed, so three requests from a single
+/// IP locked any guest out of their own account, repeatable every 15 minutes, indefinitely. The
+/// tier meant to protect a guest was the easiest way to attack them.
+///
+/// Raised deliberately far above the per-IP tier so the two do different jobs. The per-(IP, name)
+/// bucket is what stops a guesser, and it costs the ATTACKER. This tier is the last line against
+/// a DISTRIBUTED guesser, and it is the only one an attacker can turn on a victim — so reaching
+/// it must require at least three distinct sources inside the decay window.
+///
+/// Brute-force cost is unchanged: 12 attempts per 15 minutes is 48/hour against one account, so
+/// 10 000 four-digit PINs still take ~208 hours no matter how many IPs are used. An honest guest
+/// fat-fingering a 4-digit PIN never comes close, and `increment_failed_pin` now decays the
+/// streak after 15 minutes so yesterday's typos don't count toward today's.
+const PIN_LOCK_THRESHOLD: i16 = 12;
+
 #[derive(Deserialize)]
 pub struct RecoverRequest {
     pub display_name: String,
@@ -121,31 +218,94 @@ pub struct RecoverResponse {
     pub user_id: Uuid,
 }
 
+/// A real cost-12 bcrypt hash of a fixed dummy value, computed once and cached. Used
+/// to run a constant-time-ish verify on the "unknown display name" branch of
+/// [`recover`], so that branch costs the same as a real (user-exists) verify and can't
+/// be told apart by timing.
+fn dummy_pin_hash() -> &'static str {
+    static HASH: std::sync::OnceLock<String> = std::sync::OnceLock::new();
+    HASH.get_or_init(|| {
+        bcrypt::hash("eventsnap-dummy-not-a-real-pin", 12)
+            .expect("bcrypt hashing of a static dummy value cannot fail")
+    })
+}
+
+/// Run a bcrypt verify on the blocking pool.
+///
+/// bcrypt at cost 12 is ~200ms of deliberate CPU. Called inline on an async task it pins a
+/// tokio WORKER thread for that whole time, and the runtime only has one per core — so a
+/// flood of `/recover` or `/admin/login` attempts stalls every other request on the box,
+/// including the feed. Offloading moves that cost to the blocking pool, which is sized for
+/// exactly this and whose saturation degrades logins rather than the whole app.
+async fn verify_password(candidate: String, hash: String) -> bool {
+    tokio::task::spawn_blocking(move || bcrypt::verify(&candidate, &hash).unwrap_or(false))
+        .await
+        .unwrap_or(false)
+}
+
+/// Hash a secret on the blocking pool. Same reasoning as [`verify_password`] — and this one
+/// runs on the busiest auth path there is, since every guest who joins gets a PIN hashed.
+pub async fn hash_password(secret: String, cost: u32) -> Result<String, AppError> {
+    tokio::task::spawn_blocking(move || bcrypt::hash(&secret, cost))
+        .await
+        .map_err(|e| AppError::Internal(anyhow::anyhow!(e)))?
+        .map_err(|e| AppError::Internal(anyhow::anyhow!(e)))
+}
+
 pub async fn recover(
     State(state): State<AppState>,
+    ConnectInfo(peer): ConnectInfo<SocketAddr>,
     headers: HeaderMap,
     Json(body): Json<RecoverRequest>,
 ) -> Result<Json<RecoverResponse>, AppError> {
-    let display_name = body.display_name.trim();
+    // Validated BEFORE it is used as a rate-limiter key — see `validate_display_name`. The
+    // per-IP ceiling below is keyed only on the IP, so it is safe to run either side of this;
+    // the per-NAME bucket is not.
+    let display_name = validate_display_name(&body.display_name)?;
 
-    // Per-IP+name throttle BEFORE the per-user 3-strike counter. Without this
-    // an attacker who knows a display name (they're visible on the feed) can
-    // burn through 3 wrong PINs and lock the victim for 15 minutes — repeated
-    // every 15 minutes, indefinitely. 5 attempts per 15 minutes per (IP, name)
-    // softens that into a real cost.
-    let ip = client_ip(&headers, "unknown");
-    let rate_limits_on = config::get_bool(&state.pool, "rate_limits_enabled", true).await;
-    let recover_rate_on = config::get_bool(&state.pool, "recover_rate_enabled", true).await;
+    // Per-IP+name throttle BEFORE the per-user lockout counter. Without this an attacker who
+    // knows a display name (they're visible on the feed) can burn through the victim's wrong-PIN
+    // budget and lock them out, repeatedly. The ceiling here MUST stay below
+    // PIN_LOCK_THRESHOLD — see the constant for why that ordering is the whole control.
+    let ip = client_ip(&headers, &peer.ip().to_string());
+    let rate_limits_on = config::get_bool(&state.config_cache, "rate_limits_enabled", true).await;
+    let recover_rate_on = config::get_bool(&state.config_cache, "recover_rate_enabled", true).await;
     if rate_limits_on && recover_rate_on {
+        // Coarse per-IP ceiling FIRST. The per-(ip, name) bucket below is the anti-guessing
+        // control, but the name is attacker-chosen, so cycling names mints a fresh bucket
+        // every time and leaves the per-IP cost unbounded. That matters more here than
+        // anywhere else: every call runs a cost-12 bcrypt verify, including an
+        // unconditional throwaway one for names that don't exist (see below), so an unknown
+        // name is the CHEAPEST way to make the server do ~200ms of hashing. Checked before
+        // the per-name bucket so a name generator can't walk past it.
+        let ip_ceiling =
+            config::get_usize(&state.config_cache, "recover_ip_rate_per_min", 30).await;
+        if let Err(retry_after_secs) = state.rate_limiter.check_with_retry(
+            format!("recover_ip:{ip}"),
+            ip_ceiling,
+            Duration::from_secs(60),
+        ) {
+            return Err(AppError::TooManyRequests(
+                "Zu viele Versuche. Bitte warte kurz und versuche es erneut.".into(),
+                Some(retry_after_secs),
+            ));
+        }
+
+        let name_ceiling = config::get_usize(
+            &state.config_cache,
+            "recover_name_rate_per_15min",
+            RECOVER_NAME_CEILING_DEFAULT,
+        )
+        .await;
         let name_key = display_name.to_lowercase();
-        if !state.rate_limiter.check(
+        if let Err(retry_after_secs) = state.rate_limiter.check_with_retry(
             format!("recover:{ip}:{name_key}"),
-            5,
+            name_ceiling,
             Duration::from_secs(15 * 60),
         ) {
             return Err(AppError::TooManyRequests(
                 "Zu viele Versuche. Bitte warte kurz und versuche es erneut.".into(),
-                None,
+                Some(retry_after_secs),
             ));
         }
     }
@@ -154,13 +314,16 @@ pub async fn recover(
         .await?
         .ok_or_else(|| AppError::NotFound("Event nicht gefunden.".into()))?;
 
-    let users =
-        User::find_by_event_and_name(&state.pool, event.id, display_name).await?;
+    let users = User::find_by_event_and_name(&state.pool, event.id, display_name).await?;
 
     if users.is_empty() {
-        return Err(AppError::NotFound(
-            "Kein Benutzer mit diesem Namen gefunden.".into(),
-        ));
+        // No user with this name. Run a throwaway bcrypt verify so this branch takes
+        // the same time as the user-exists path, and return the SAME error as a wrong
+        // PIN — so "no such name" and "wrong PIN" are indistinguishable by response or
+        // timing. Display names are already public on the feed, but this still closes
+        // the /recover enumeration + timing oracle.
+        let _ = verify_password(body.pin.clone(), dummy_pin_hash().to_string()).await;
+        return Err(AppError::Unauthorized("PIN ist falsch.".into()));
     }
 
     for user in &users {
@@ -171,17 +334,19 @@ pub async fn recover(
         // is effectively permanently fragile.
         if let Some(locked_until) = user.pin_locked_until {
             if Utc::now() < locked_until {
+                // The exact deadline is known, so surface it as Retry-After instead of
+                // making the client guess at the "15 Minuten" in the copy.
+                let retry_after_secs = (locked_until - Utc::now()).num_seconds().max(1) as u64;
                 return Err(AppError::TooManyRequests(
                     "Zu viele Versuche. Bitte warte 15 Minuten.".into(),
-                    None,
+                    Some(retry_after_secs),
                 ));
             }
             // Lockout window expired — wipe the counter and the timestamp.
             User::reset_pin_attempts(&state.pool, user.id).await?;
         }
 
-        let pin_matches = bcrypt::verify(&body.pin, &user.recovery_pin_hash)
-            .unwrap_or(false);
+        let pin_matches = verify_password(body.pin.clone(), user.recovery_pin_hash.clone()).await;
 
         if pin_matches {
             // Reset failed attempts on success
@@ -215,7 +380,7 @@ pub async fn recover(
             attempts,
             "recover: wrong PIN"
         );
-        if attempts >= 3 {
+        if attempts >= PIN_LOCK_THRESHOLD {
             let lockout = Utc::now() + chrono::Duration::minutes(15);
             User::lock_pin(&state.pool, user.id, lockout).await?;
             tracing::warn!(
@@ -238,10 +403,15 @@ pub struct AdminLoginRequest {
 #[derive(Serialize)]
 pub struct AdminLoginResponse {
     pub jwt: String,
+    /// The admin's user id + display name, so the client can populate a real identity
+    /// (own-post affordances, a name on the Account page) instead of a blank session.
+    pub user_id: Uuid,
+    pub display_name: String,
 }
 
 pub async fn admin_login(
     State(state): State<AppState>,
+    ConnectInfo(peer): ConnectInfo<SocketAddr>,
     headers: HeaderMap,
     Json(body): Json<AdminLoginRequest>,
 ) -> Result<Json<AdminLoginResponse>, AppError> {
@@ -255,11 +425,15 @@ pub async fn admin_login(
     // verify) but with no IP-level limit a determined attacker can still mount
     // a long-running guess campaign. 5 attempts / minute / IP is plenty for
     // honest typos.
-    let ip = client_ip(&headers, "unknown");
-    let rate_limits_on = config::get_bool(&state.pool, "rate_limits_enabled", true).await;
-    let admin_rate_on = config::get_bool(&state.pool, "admin_login_rate_enabled", true).await;
-    if rate_limits_on && admin_rate_on
-        && !state.rate_limiter.check(
+    let ip = client_ip(&headers, &peer.ip().to_string());
+    let rate_limits_on = config::get_bool(&state.config_cache, "rate_limits_enabled", true).await;
+    let admin_rate_on =
+        config::get_bool(&state.config_cache, "admin_login_rate_enabled", true).await;
+    // Stays keyed by IP on purpose: this guards a single shared credential, so a per-user
+    // or per-name key would just hand an attacker a fresh bucket per guess.
+    if rate_limits_on
+        && admin_rate_on
+        && let Err(retry_after_secs) = state.rate_limiter.check_with_retry(
             format!("admin_login:{ip}"),
             5,
             Duration::from_secs(60),
@@ -267,12 +441,15 @@ pub async fn admin_login(
     {
         return Err(AppError::TooManyRequests(
             "Zu viele Anmeldeversuche. Bitte warte kurz und versuche es erneut.".into(),
-            None,
+            Some(retry_after_secs),
         ));
     }
 
-    let valid = bcrypt::verify(&body.password, &state.config.admin_password_hash)
-        .unwrap_or(false);
+    let valid = verify_password(
+        body.password.clone(),
+        state.config.admin_password_hash.clone(),
+    )
+    .await;
 
     if !valid {
         tracing::warn!(ip = %ip, "admin_login: wrong password");
@@ -286,28 +463,16 @@ pub async fn admin_login(
     )
     .await?;
 
-    // Find or create the admin user for this event
-    let admin_name = "Admin";
-    let users = User::find_by_event_and_name(&state.pool, event.id, admin_name).await?;
-    let admin_user = if let Some(u) = users.into_iter().find(|u| u.role == UserRole::Admin) {
-        u
-    } else {
-        // Admin authenticates via password, but the schema still requires a PIN
-        // hash. Generate a random unguessable PIN so the recovery path remains
-        // unusable as an escalation route even if the role flag ever got cleared.
-        let dummy_pin: String = (0..32)
-            .map(|_| rand::rng().random_range(b'a'..=b'z') as char)
-            .collect();
-        let dummy_hash = bcrypt::hash(&dummy_pin, 4)
-            .map_err(|e| AppError::Internal(anyhow::anyhow!(e)))?;
-        let user = User::create(&state.pool, event.id, admin_name, &dummy_hash).await?;
-        sqlx::query("UPDATE \"user\" SET role = 'admin' WHERE id = $1")
-            .bind(user.id)
-            .execute(&state.pool)
-            .await?;
-        User::find_by_id(&state.pool, user.id)
-            .await?
-            .ok_or_else(|| AppError::Internal(anyhow::anyhow!("admin user creation failed")))?
+    // Find or create the admin user for this event — BY ROLE, never by name.
+    //
+    // The name lookup this replaces is what made admin login brickable. Migration 007 makes
+    // display_name unique per event case-insensitively and `join` had no reserved-name guard,
+    // so a guest joining as "admin" before the operator's first login made the lookup miss on
+    // role, the fallback `create("Admin")` violate that index, and `?` return a permanent 500 —
+    // taking out moderation, config and gallery release with no in-app recovery.
+    let admin_user = match User::find_admin_for_event(&state.pool, event.id).await? {
+        Some(u) => u,
+        None => create_admin_user(&state, event.id).await?,
     };
 
     tracing::info!(user_id = %admin_user.id, event_id = %event.id, ip = %ip, "admin_login: success");
@@ -325,13 +490,219 @@ pub async fn admin_login(
     let expires_at = Utc::now() + chrono::Duration::days(1);
     Session::create(&state.pool, admin_user.id, &token_hash, expires_at).await?;
 
-    Ok(Json(AdminLoginResponse { jwt: token }))
+    Ok(Json(AdminLoginResponse {
+        jwt: token,
+        user_id: admin_user.id,
+        display_name: admin_user.display_name,
+    }))
 }
 
-pub async fn logout(
-    State(state): State<AppState>,
-    auth: AuthUser,
-) -> Result<StatusCode, AppError> {
+/// Create this event's admin row on first successful admin login.
+///
+/// Prefers the name "Admin". If a legacy database has a guest squatting on it — the state
+/// migration 023 renames away, but a row could also predate that or be created between
+/// migrations — falls back to a suffixed name rather than failing the login.
+///
+/// PROMOTING THE SQUATTING ROW WOULD BE A SERIOUS MISTAKE, and is the obvious-looking fix, so
+/// it is spelled out: that row carries a `recovery_pin_hash` the guest knows. Setting
+/// `role = 'admin'` on it would hand them the admin dashboard through `/recover`, permanently,
+/// via a path that needs no password. A separate row under an uglier name is worse UX and much
+/// better security — and since the lookup is now by role, the fallback name never has to be
+/// guessed again on a later login.
+async fn create_admin_user(state: &AppState, event_id: Uuid) -> Result<User, AppError> {
+    // Admin authenticates via password, but the schema still requires a PIN hash. Generate a
+    // random unguessable one so the recovery path stays unusable as an escalation route even if
+    // the role flag were ever cleared.
+    let dummy_pin: String = (0..32)
+        .map(|_| rand::rng().random_range(b'a'..=b'z') as char)
+        .collect();
+    let dummy_hash = hash_password(dummy_pin, 4).await?;
+
+    match User::create_with_role(&state.pool, event_id, "Admin", &dummy_hash, UserRole::Admin).await
+    {
+        Ok(u) => Ok(u),
+        Err(sqlx::Error::Database(db)) if db.is_unique_violation() => {
+            let fallback = format!("Admin-{}", &Uuid::new_v4().to_string()[..8]);
+            tracing::warn!(
+                %event_id, %fallback,
+                "the name \"Admin\" is held by a non-admin user; creating the admin under a \
+                 fallback name. Rename that guest to free it — do NOT promote their row, they \
+                 know its recovery PIN."
+            );
+            Ok(User::create_with_role(
+                &state.pool,
+                event_id,
+                &fallback,
+                &dummy_hash,
+                UserRole::Admin,
+            )
+            .await?)
+        }
+        Err(e) => Err(e.into()),
+    }
+}
+
+pub async fn logout(State(state): State<AppState>, auth: AuthUser) -> Result<StatusCode, AppError> {
     Session::delete_by_token_hash(&state.pool, &auth.token_hash).await?;
     Ok(StatusCode::NO_CONTENT)
 }
+
+/// "Sign out everywhere" — revoke every session for the caller, not just the current one.
+/// A single leaked/kept-alive device (a shared phone, a laptop recovered via PIN) can then
+/// be cut from any of the user's devices.
+pub async fn logout_all(
+    State(state): State<AppState>,
+    auth: AuthUser,
+) -> Result<StatusCode, AppError> {
+    Session::delete_all_for_user(&state.pool, auth.user_id).await?;
+    Ok(StatusCode::NO_CONTENT)
+}
+
+#[derive(Deserialize)]
+pub struct PinResetRequestBody {
+    pub display_name: String,
+}
+
+/// A guest who forgot their PIN asks a host to reset it in-app. Unauthenticated (they
+/// can't log in without the PIN) and rate-limited. Always returns 204 regardless of
+/// whether the name exists, so it can't enumerate display names beyond what the public
+/// feed already exposes.
+pub async fn request_pin_reset(
+    State(state): State<AppState>,
+    ConnectInfo(peer): ConnectInfo<SocketAddr>,
+    headers: HeaderMap,
+    Json(body): Json<PinResetRequestBody>,
+) -> Result<StatusCode, AppError> {
+    let ip = client_ip(&headers, &peer.ip().to_string());
+    let rate_limits_on = config::get_bool(&state.config_cache, "rate_limits_enabled", true).await;
+
+    // Coarse per-IP ceiling FIRST, keyed only on the IP so its key is bounded by construction.
+    // /join got one of these in migration 017 and /recover in 019; this third unauthenticated
+    // endpoint was simply missed — migration 019's own comment describes exactly this attack.
+    // Without it, the per-name bucket below is no ceiling at all: the name is attacker-chosen,
+    // so cycling names mints a fresh bucket every request.
+    if rate_limits_on {
+        let ip_ceiling =
+            config::get_usize(&state.config_cache, "pin_reset_ip_rate_per_min", 30).await;
+        if let Err(retry_after_secs) = state.rate_limiter.check_with_retry(
+            format!("pin_reset_ip:{ip}"),
+            ip_ceiling,
+            Duration::from_secs(60),
+        ) {
+            return Err(AppError::TooManyRequests(
+                "Zu viele Anfragen. Bitte warte kurz und versuche es erneut.".into(),
+                Some(retry_after_secs),
+            ));
+        }
+    }
+
+    // Validated BEFORE the per-name key is built, so an unbounded name can never be retained in
+    // the limiter map. NOTE the 204: this endpoint's contract is that it answers identically
+    // whether or not the name exists, so it cannot enumerate guests. A 400 here would be a new
+    // signal — it would distinguish a malformed name from a well-formed unknown one. Silence is
+    // the correct response, and matches what an empty name already did.
+    let Ok(display_name) = validate_display_name(&body.display_name) else {
+        return Ok(StatusCode::NO_CONTENT);
+    };
+
+    if rate_limits_on {
+        let name_key = display_name.to_lowercase();
+        if let Err(retry_after_secs) = state.rate_limiter.check_with_retry(
+            format!("pin_reset_req:{ip}:{name_key}"),
+            3,
+            Duration::from_secs(15 * 60),
+        ) {
+            return Err(AppError::TooManyRequests(
+                "Zu viele Anfragen. Bitte warte kurz und versuche es erneut.".into(),
+                Some(retry_after_secs),
+            ));
+        }
+    }
+
+    // Single statement so the existing-name and unknown-name paths do IDENTICAL work
+    // (same event+user index scans, an INSERT that matches 0 rows for an unknown name) —
+    // no timing oracle despite the always-204 contract. Admins recover via password, so
+    // they're excluded from the join and never get a reset request queued.
+    let _ = sqlx::query(
+        "INSERT INTO pin_reset_request (event_id, user_id)
+         SELECT e.id, u.id
+         FROM event e
+         JOIN \"user\" u
+           ON u.event_id = e.id
+          AND lower(u.display_name) = lower($2)
+          AND u.role <> 'admin'
+         WHERE e.slug = $1
+         ON CONFLICT (user_id) DO NOTHING",
+    )
+    .bind(&state.config.event_slug)
+    .bind(display_name)
+    .execute(&state.pool)
+    .await;
+
+    // Broadcast unconditionally (carries no per-name info) so an online host's request
+    // badge updates without revealing whether the name existed.
+    let _ = state
+        .sse_tx
+        .send(crate::state::SseEvent::new("pin-reset-requested", "{}"));
+
+    Ok(StatusCode::NO_CONTENT)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// THE defect, stated as arithmetic: the account-lock threshold sat BELOW the per-(IP, name)
+    /// attempt ceiling, so a single IP could exhaust it and lock any guest whose display name is
+    /// visible on the feed — every 15 minutes, indefinitely. The tier meant to protect a guest
+    /// was the cheapest way to attack them.
+    ///
+    /// The fix is the ORDERING, not either number on its own, so that is what this pins.
+    #[test]
+    fn one_ip_cannot_reach_the_account_lock() {
+        assert!(
+            PIN_LOCK_THRESHOLD as usize >= RECOVER_NAME_CEILING_DEFAULT * 3,
+            "locking a victim must require at least three distinct sources; \
+             threshold {PIN_LOCK_THRESHOLD} vs per-IP ceiling {RECOVER_NAME_CEILING_DEFAULT}"
+        );
+    }
+
+    /// Raising the threshold must not quietly weaken brute-force resistance. 4-digit PINs, and
+    /// the lockout window is 15 minutes, so an attacker gets PIN_LOCK_THRESHOLD tries per window.
+    #[test]
+    fn the_raised_threshold_still_makes_guessing_a_four_digit_pin_impractical() {
+        let attempts_per_hour = PIN_LOCK_THRESHOLD as u64 * 4; // four 15-minute windows
+        let hours_for_full_keyspace = 10_000 / attempts_per_hour;
+        assert!(
+            hours_for_full_keyspace >= 168,
+            "exhausting 10k PINs would take {hours_for_full_keyspace}h — under a week is too fast"
+        );
+    }
+
+    #[test]
+    fn reserved_names_are_matched_case_insensitively_and_trimmed() {
+        for name in ["admin", "Admin", "ADMIN", "  Host  ", "EventSnap"] {
+            assert!(is_reserved_display_name(name), "{name} must be reserved");
+        }
+    }
+
+    /// A substring match here would reject perfectly ordinary names, which is a worse outcome
+    /// than the impersonation the list guards against.
+    #[test]
+    fn names_that_merely_contain_a_reserved_word_are_allowed() {
+        for name in ["Administrata", "Hostess", "Adminah", "Ghost", "hosting"] {
+            assert!(!is_reserved_display_name(name), "{name} must be allowed");
+        }
+    }
+
+    #[test]
+    fn display_names_are_bounded_before_they_can_become_a_rate_limit_key() {
+        assert!(validate_display_name("  Lena  ").is_ok());
+        assert_eq!(validate_display_name("  Lena  ").unwrap(), "Lena");
+        // The case that made the limiter itself the exhaustion primitive.
+        assert!(validate_display_name(&"a".repeat(51)).is_err());
+        assert!(validate_display_name(&"a".repeat(2_000_000)).is_err());
+        assert!(validate_display_name("   ").is_err());
+        assert!(validate_display_name("bad\0name").is_err());
+    }
+}

backend/src/auth/jwt.rs

@@ -46,10 +46,20 @@ pub fn create_token(
 }
 
 pub fn verify_token(token: &str, secret: &str) -> Result<Claims, jsonwebtoken::errors::Error> {
+    // We deliberately do NOT enforce the JWT's own `exp`. The authoritative session
+    // lifetime lives in the `session` row (`expires_at > NOW()`), which SLIDES forward on
+    // every authenticated request (see `Session::touch_and_renew`). Enforcing the JWT's
+    // fixed +Nd `exp` here would hard-log-out an actively-used client on day N+1 even
+    // though its session was renewed — the "30-day cliff" from the review. With server-
+    // side sliding sessions, the token is a signature-checked bearer credential and its
+    // lifetime is revocable (logout / expiry / ban all delete the row), which is strictly
+    // stronger than a stateless non-revocable exp.
+    let mut validation = Validation::default();
+    validation.validate_exp = false;
     let data = jsonwebtoken::decode::<Claims>(
         token,
         &DecodingKey::from_secret(secret.as_bytes()),
-        &Validation::default(),
+        &validation,
     )?;
     Ok(data.claims)
 }

backend/src/auth/middleware.rs

@@ -37,34 +37,43 @@ impl FromRequestParts<AppState> for AuthUser {
             .strip_prefix("Bearer ")
             .ok_or_else(|| AppError::Unauthorized("Ungültiges Token-Format.".into()))?;
 
-        let claims = jwt::verify_token(token, &state.config.jwt_secret)
+        // Verify the JWT's signature. Expiry is deliberately NOT enforced here (see
+        // `jwt::verify_token`) — the authoritative, sliding session lifetime lives in the
+        // `session` row read below. We also don't trust the token's role/ban claims; the
+        // live user row is authoritative, so the decoded claims aren't needed beyond this.
+        jwt::verify_token(token, &state.config.jwt_secret)
             .map_err(|_| AppError::Unauthorized("Token ungültig oder abgelaufen.".into()))?;
 
         let token_hash = jwt::hash_token(token);
 
-        let session = Session::find_by_token_hash(&state.pool, &token_hash)
+        // Single round-trip: resolve the session token to its *live* user row. A
+        // role/ban stored in the token would survive a demote/ban for the full session
+        // lifetime (up to 30d), so we always re-read the user (a demoted host loses host
+        // powers immediately). We do NOT reject banned users here — they retain read
+        // access by design; writes and host/admin actions enforce the ban downstream.
+        let user = Session::find_user_by_token_hash(&state.pool, &token_hash)
             .await
             .map_err(|e| AppError::Internal(e.into()))?
-            .ok_or_else(|| AppError::Unauthorized("Sitzung nicht gefunden oder abgelaufen.".into()))?;
+            .ok_or_else(|| {
+                AppError::Unauthorized("Sitzung nicht gefunden oder abgelaufen.".into())
+            })?;
 
-        // Trust *live* DB state, not the JWT: a role/ban stored in the token would
-        // survive a demote/ban for the full session lifetime (up to 30d). Re-read
-        // the user row so a demoted host loses host powers immediately. We do NOT
-        // reject banned users here — they retain read access by design; writes and
-        // host/admin actions enforce the ban downstream.
-        let user = crate::models::user::User::find_by_id(&state.pool, claims.sub)
-            .await
-            .map_err(|e| AppError::Internal(e.into()))?
-            .ok_or_else(|| AppError::Unauthorized("Benutzer nicht gefunden.".into()))?;
-
-        // Update last_seen_at in the background (fire-and-forget). Failures are
-        // non-fatal but worth surfacing — silent swallowing hides DB connection
-        // pressure that would otherwise be the first symptom of a real problem.
+        // Touch last_seen_at AND slide the session's expiry forward (fire-and-forget), so
+        // an active client's session renews instead of hitting the fixed 30-day cliff.
+        // Admin sessions keep their tighter 1-day window (they renew on activity but still
+        // lapse a day after the admin goes idle). Failures are non-fatal but worth
+        // surfacing — silent swallowing hides DB connection pressure that would otherwise
+        // be the first symptom of a real problem.
         let pool = state.pool.clone();
-        let session_id = session.id;
+        let touch_hash = token_hash.clone();
+        let expiry_days = if user.role == UserRole::Admin {
+            1
+        } else {
+            state.config.session_expiry_days
+        };
         tokio::spawn(async move {
-            if let Err(e) = Session::touch(&pool, session_id).await {
-                tracing::warn!(error = ?e, session_id = %session_id, "session touch failed");
+            if let Err(e) = Session::touch_and_renew(&pool, &touch_hash, expiry_days).await {
+                tracing::warn!(error = ?e, "session touch/renew failed");
             }
         });
 

backend/src/config.rs

@@ -1,6 +1,6 @@
 use std::path::PathBuf;
 
-use anyhow::{anyhow, Context, Result};
+use anyhow::{Context, Result, anyhow};
 
 /// Well-known dev JWT secret shipped in `.env.example`. If APP_ENV=production
 /// we refuse to start with this value; otherwise we warn loudly.
@@ -20,21 +20,53 @@ fn looks_placeholder(s: &str) -> bool {
 /// Enforce secret hygiene. In production every guard is hard-fail: a booting app
 /// with a publicly-known signing key is worse than one that refuses to start.
 /// Outside production the dev sentinel is tolerated (warned) so local dev is frictionless.
-fn validate_secrets(is_prod: bool, jwt_secret: &str, admin_password_hash: &str) -> Result<()> {
+///
+/// EVERY failure is collected and reported together. Returning on the first one made fixing two
+/// secrets cost two boot cycles — the operator rotates JWT_SECRET, restarts, and only then learns
+/// about ADMIN_PASSWORD_HASH. Restarting this stack is not free (Caddy waits on the unhealthy app),
+/// and each avoidable cycle is another chance to reach for `down -v`.
+fn validate_secrets(
+    is_prod: bool,
+    jwt_secret: &str,
+    admin_password_hash: &str,
+    database_url: &str,
+) -> Result<()> {
     if is_prod {
+        let mut problems: Vec<&str> = Vec::new();
         if looks_placeholder(jwt_secret) {
-            return Err(anyhow!(
-                "Refusing to start in production with a placeholder JWT_SECRET — \
-                 rotate it (openssl rand -hex 64)."
-            ));
-        }
-        if jwt_secret.len() < 32 {
-            return Err(anyhow!("JWT_SECRET must be at least 32 characters."));
+            problems.push(
+                "JWT_SECRET is still the .env.example placeholder — rotate it \
+                 (openssl rand -hex 64).",
+            );
+        } else if jwt_secret.len() < 32 {
+            problems.push("JWT_SECRET must be at least 32 characters.");
         }
         if admin_password_hash.is_empty() || looks_placeholder(admin_password_hash) {
+            problems.push(
+                "ADMIN_PASSWORD_HASH is unset or still the .env.example placeholder — generate one \
+                 (docker run --rm caddy:2-alpine caddy hash-password --plaintext '<password>').",
+            );
+        }
+        // The DATABASE_URL carries the Postgres password, so a placeholder here means the stack is
+        // running on `CHANGE_ME_use_a_strong_password` — a credential published in the repo. The
+        // app used to boot green on it, because this guard only ever covered the two secrets it
+        // was written for and nothing else looked at POSTGRES_PASSWORD at all.
+        //
+        // Read POSTGRES_PASSWORD's docs before changing this: it is applied ONLY at initdb, so the
+        // remedy is not "edit .env and restart" — see the 28P01 diagnostic in db.rs.
+        if looks_placeholder(database_url) {
+            problems.push(
+                "DATABASE_URL still carries the .env.example placeholder password — set a strong \
+                 one (openssl rand -hex 24) in BOTH DATABASE_URL and POSTGRES_PASSWORD.",
+            );
+        }
+        if !problems.is_empty() {
             return Err(anyhow!(
-                "Refusing to start in production without a real ADMIN_PASSWORD_HASH — \
-                 generate one (htpasswd -bnBC 12 '' <password> | tr -d ':\\n')."
+                "Refusing to start in production — {} secret(s) still unset or placeholder:\n  - {}\n\
+                 ALL secrets must be set BEFORE the first `docker compose up -d`: Postgres bakes \
+                 POSTGRES_PASSWORD into its data directory on first boot and ignores later changes.",
+                problems.len(),
+                problems.join("\n  - ")
             ));
         }
     } else if jwt_secret == DEV_JWT_SECRET_SENTINEL {
@@ -63,32 +95,46 @@ pub struct AppConfig {
     pub app_port: u16,
     /// Number of concurrent media compression workers (read once at boot).
     pub compression_concurrency: usize,
+    /// Master switch for the comment feature (env `COMMENTS_ENABLED`, default true).
+    /// When false the backend rejects new comments and the frontend hides the whole
+    /// comment UI. Existing comments stay in the DB (hidden), so flipping it back
+    /// restores them. Boot-time immutable, like `compression_concurrency`.
+    pub comments_enabled: bool,
+    /// Default colour theme, used as the fallback when the DB config keys are unset.
+    /// Runtime overrides live in the `config` table (admin UI); these env vars only
+    /// seed the initial default. `preset` is an id the frontend knows (e.g.
+    /// "champagne-gold", "rose", … or "custom"); the two seeds are `#rrggbb` brand +
+    /// accent colours the whole palette is derived from.
+    pub default_theme_preset: String,
+    pub default_theme_primary: String,
+    pub default_theme_accent: String,
 }
 
+/// The shipped default brand/accent seed (champagne gold — matches the hand-tuned
+/// ramp in tailwind-theme.css). Kept here so an unset env still yields the current look.
+const DEFAULT_THEME_SEED: &str = "#8a6a2b";
+
 impl AppConfig {
     pub fn from_env() -> Result<Self> {
-        let app_env =
-            std::env::var("APP_ENV").unwrap_or_else(|_| "development".to_string());
+        let app_env = std::env::var("APP_ENV").unwrap_or_else(|_| "development".to_string());
         let is_prod = app_env.eq_ignore_ascii_case("production");
 
         let jwt_secret = std::env::var("JWT_SECRET").context("JWT_SECRET must be set")?;
         let admin_password_hash = std::env::var("ADMIN_PASSWORD_HASH").unwrap_or_default();
+        let database_url = std::env::var("DATABASE_URL").context("DATABASE_URL must be set")?;
 
-        validate_secrets(is_prod, &jwt_secret, &admin_password_hash)?;
+        validate_secrets(is_prod, &jwt_secret, &admin_password_hash, &database_url)?;
 
         Ok(Self {
-            database_url: std::env::var("DATABASE_URL")
-                .context("DATABASE_URL must be set")?,
+            database_url,
             jwt_secret,
             session_expiry_days: std::env::var("SESSION_EXPIRY_DAYS")
                 .unwrap_or_else(|_| "30".to_string())
                 .parse()
                 .context("SESSION_EXPIRY_DAYS must be a number")?,
             admin_password_hash,
-            event_name: std::env::var("EVENT_NAME")
-                .unwrap_or_else(|_| "EventSnap".to_string()),
-            event_slug: std::env::var("EVENT_SLUG")
-                .context("EVENT_SLUG must be set")?,
+            event_name: std::env::var("EVENT_NAME").unwrap_or_else(|_| "EventSnap".to_string()),
+            event_slug: std::env::var("EVENT_SLUG").context("EVENT_SLUG must be set")?,
             media_path: PathBuf::from(
                 std::env::var("MEDIA_PATH").unwrap_or_else(|_| "/media".to_string()),
             ),
@@ -104,6 +150,20 @@ impl AppConfig {
                 .and_then(|v| v.parse().ok())
                 .filter(|&n| n >= 1)
                 .unwrap_or(2),
+            comments_enabled: std::env::var("COMMENTS_ENABLED")
+                .map(|v| {
+                    !matches!(
+                        v.trim().to_ascii_lowercase().as_str(),
+                        "false" | "0" | "no" | "off"
+                    )
+                })
+                .unwrap_or(true),
+            default_theme_preset: std::env::var("THEME_PRESET")
+                .unwrap_or_else(|_| "champagne-gold".to_string()),
+            default_theme_primary: std::env::var("THEME_PRIMARY")
+                .unwrap_or_else(|_| DEFAULT_THEME_SEED.to_string()),
+            default_theme_accent: std::env::var("THEME_ACCENT")
+                .unwrap_or_else(|_| DEFAULT_THEME_SEED.to_string()),
         })
     }
 }
@@ -114,48 +174,152 @@ mod tests {
 
     const REAL_SECRET: &str = "a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2";
     const REAL_HASH: &str = "$2y$12$abcdefghijklmnopqrstuv.wxyzABCDEFGHIJKLMNOPQRSTUVWXYZ012";
+    const REAL_DB_URL: &str = "postgres://eventsnap:7f3a9c1e5b2d8a4f@db:5432/eventsnap";
 
     #[test]
     fn prod_rejects_shipped_placeholder_secret() {
         // The exact string shipped in `.env` — >32 chars, so it must be caught by
         // the substring guard, not the length check.
-        let err = validate_secrets(true, "change_me_to_a_random_64_byte_hex_string", REAL_HASH);
-        assert!(err.is_err(), "placeholder JWT_SECRET must be rejected in prod");
+        let err = validate_secrets(
+            true,
+            "change_me_to_a_random_64_byte_hex_string",
+            REAL_HASH,
+            REAL_DB_URL,
+        );
+        assert!(
+            err.is_err(),
+            "placeholder JWT_SECRET must be rejected in prod"
+        );
     }
 
     #[test]
     fn prod_rejects_dev_sentinel_and_short_secret() {
-        assert!(validate_secrets(true, DEV_JWT_SECRET_SENTINEL, REAL_HASH).is_err());
-        assert!(validate_secrets(true, "tooshort", REAL_HASH).is_err());
+        assert!(validate_secrets(true, DEV_JWT_SECRET_SENTINEL, REAL_HASH, REAL_DB_URL).is_err());
+        assert!(validate_secrets(true, "tooshort", REAL_HASH, REAL_DB_URL).is_err());
     }
 
     #[test]
     fn prod_rejects_missing_or_placeholder_admin_hash() {
-        assert!(validate_secrets(true, REAL_SECRET, "").is_err());
-        assert!(validate_secrets(true, REAL_SECRET, "$2y$12$placeholder_replace_me").is_err());
+        assert!(validate_secrets(true, REAL_SECRET, "", REAL_DB_URL).is_err());
+        assert!(
+            validate_secrets(
+                true,
+                REAL_SECRET,
+                "$2y$12$placeholder_replace_me",
+                REAL_DB_URL
+            )
+            .is_err()
+        );
+    }
+
+    /// The stack used to come up GREEN on the database password published in the repo: this guard
+    /// covered the two secrets it was written for, and nothing anywhere looked at the Postgres
+    /// credential. README step 2 doesn't name POSTGRES_PASSWORD either, so following the
+    /// documented procedure verbatim shipped it.
+    #[test]
+    fn prod_rejects_the_shipped_placeholder_database_password() {
+        let shipped = "postgres://eventsnap:CHANGE_ME_use_a_strong_password@db:5432/eventsnap";
+        let err = validate_secrets(true, REAL_SECRET, REAL_HASH, shipped).unwrap_err();
+        assert!(
+            err.to_string().contains("DATABASE_URL"),
+            "the refusal must name DATABASE_URL, not just fail: {err}"
+        );
+        // And it must point at the initdb trap, or the operator edits .env, restarts, and lands
+        // in a permanent auth-failure loop instead.
+        assert!(
+            err.to_string().contains("POSTGRES_PASSWORD"),
+            "the refusal must name POSTGRES_PASSWORD as the other half: {err}"
+        );
+    }
+
+    /// Every problem in ONE message. Reporting them one per boot made fixing two secrets cost two
+    /// restart cycles, on a stack where Caddy waits on the unhealthy app the whole time.
+    #[test]
+    fn prod_reports_every_placeholder_at_once() {
+        let err = validate_secrets(
+            true,
+            "change_me_to_a_random_64_byte_hex_string",
+            "$2y$12$placeholder_replace_me",
+            "postgres://eventsnap:CHANGE_ME_use_a_strong_password@db:5432/eventsnap",
+        )
+        .unwrap_err()
+        .to_string();
+        for expected in ["JWT_SECRET", "ADMIN_PASSWORD_HASH", "DATABASE_URL"] {
+            assert!(err.contains(expected), "{expected} missing from: {err}");
+        }
+        assert!(
+            err.contains("3 secret(s)"),
+            "the count must match what is listed: {err}"
+        );
     }
 
     #[test]
     fn prod_accepts_real_secrets() {
-        assert!(validate_secrets(true, REAL_SECRET, REAL_HASH).is_ok());
+        assert!(validate_secrets(true, REAL_SECRET, REAL_HASH, REAL_DB_URL).is_ok());
+    }
+
+    /// A real password that happens to contain no placeholder substring must pass — including one
+    /// with URL-ish punctuation, so the guard can't be mistaken for a URL validator.
+    #[test]
+    fn prod_accepts_a_real_database_url_with_awkward_punctuation() {
+        assert!(
+            validate_secrets(
+                true,
+                REAL_SECRET,
+                REAL_HASH,
+                "postgres://eventsnap:aB3%24xY9-_.qW@db:5432/eventsnap"
+            )
+            .is_ok()
+        );
+    }
+
+    /// The e2e stack runs without APP_ENV=production, so none of this applies there — but assert
+    /// it, because a guard that tripped in e2e would be found the hard way.
+    #[test]
+    fn non_prod_ignores_a_placeholder_database_url() {
+        assert!(
+            validate_secrets(
+                false,
+                REAL_SECRET,
+                "",
+                "postgres://eventsnap:CHANGE_ME_use_a_strong_password@db:5432/eventsnap"
+            )
+            .is_ok()
+        );
     }
 
     #[test]
     fn non_prod_tolerates_dev_sentinel() {
-        assert!(validate_secrets(false, DEV_JWT_SECRET_SENTINEL, "").is_ok());
+        assert!(validate_secrets(false, DEV_JWT_SECRET_SENTINEL, "", REAL_DB_URL).is_ok());
     }
 
     #[test]
     fn non_prod_still_rejects_short_non_sentinel_secret() {
-        assert!(validate_secrets(false, "tooshort", "").is_err());
+        assert!(validate_secrets(false, "tooshort", "", REAL_DB_URL).is_err());
     }
 
     #[test]
     fn placeholder_detection_is_case_insensitive() {
         // looks_placeholder lowercases before matching — an upper/mixed-case
         // placeholder must still be rejected in prod.
-        assert!(validate_secrets(true, "CHANGE_ME_TO_A_RANDOM_64_BYTE_HEX_STRING", REAL_HASH).is_err());
-        assert!(validate_secrets(true, REAL_SECRET, "$2Y$12$PLACEHOLDER_replace_me").is_err());
+        assert!(
+            validate_secrets(
+                true,
+                "CHANGE_ME_TO_A_RANDOM_64_BYTE_HEX_STRING",
+                REAL_HASH,
+                REAL_DB_URL
+            )
+            .is_err()
+        );
+        assert!(
+            validate_secrets(
+                true,
+                REAL_SECRET,
+                "$2Y$12$PLACEHOLDER_replace_me",
+                REAL_DB_URL
+            )
+            .is_err()
+        );
     }
 
     #[test]
@@ -165,7 +329,7 @@ mod tests {
         const LEN_31: &str = "abcdefghijklmnopqrstuvwxyz01234";
         assert_eq!(LEN_32.len(), 32);
         assert_eq!(LEN_31.len(), 31);
-        assert!(validate_secrets(true, LEN_32, REAL_HASH).is_ok());
-        assert!(validate_secrets(true, LEN_31, REAL_HASH).is_err());
+        assert!(validate_secrets(true, LEN_32, REAL_HASH, REAL_DB_URL).is_ok());
+        assert!(validate_secrets(true, LEN_31, REAL_HASH, REAL_DB_URL).is_err());
     }
 }

backend/src/db.rs

@@ -1,20 +1,78 @@
 use anyhow::{Context, Result};
-use sqlx::postgres::PgPoolOptions;
 use sqlx::PgPool;
+use sqlx::postgres::PgPoolOptions;
 
 const DEFAULT_MAX_CONNECTIONS: u32 = 10;
 
+/// How long a request waits for a pool connection before being shed.
+///
+/// sqlx's default is 30 s — longer than the frontend's own 20 s fetch timeout (api.ts
+/// TIMEOUT_MS), so under saturation the browser gave up while the server kept holding the
+/// slot: the client saw a timeout, the server saw a completed request, and the work was done
+/// for nobody. Failing fast sheds load instead of compounding it, and `From<sqlx::Error>` in
+/// error.rs turns the timeout into a 503 with a Retry-After rather than a bare 500.
+const ACQUIRE_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(5);
+
+/// SQLSTATE for `invalid_password`.
+const PG_INVALID_PASSWORD: &str = "28P01";
+
+/// Turn the one connect failure with an unguessable cause into a self-explaining one.
+///
+/// `POSTGRES_PASSWORD` is honoured ONLY when Postgres initialises its data directory. Change it in
+/// `.env` afterwards and the app authenticates with the new password against a volume that still
+/// holds the old one — a permanent restart loop whose only symptom is
+/// `password authentication failed`.
+///
+/// The production secret guard makes that sequence NEARLY CERTAIN rather than rare: it stops the
+/// app on the first `docker compose up -d`, but not the `db` service in that same command, which
+/// initialises and bakes in whatever password was in `.env` at that moment. So the intended
+/// recovery — see the refusal, fix your secrets, boot again — is exactly the sequence that breaks
+/// it. Nothing in the error names the cause, and the remedy destroys data, so it is the last thing
+/// an operator should guess at.
+fn explain_auth_failure(err: &sqlx::Error) {
+    let is_auth_failure = match err {
+        sqlx::Error::Database(db) => db.code().as_deref() == Some(PG_INVALID_PASSWORD),
+        _ => false,
+    };
+    if !is_auth_failure {
+        return;
+    }
+    tracing::error!(
+        "Postgres rejected the credentials in DATABASE_URL (SQLSTATE {PG_INVALID_PASSWORD}).\n\
+         \n\
+         This almost always means POSTGRES_PASSWORD was changed AFTER the database volume was \
+         first created. Postgres applies that variable only when it initialises its data \
+         directory; editing .env and restarting does not change the stored password, so the two \
+         drift apart permanently.\n\
+         \n\
+         If the event has NOT started and you have no data worth keeping:\n\n    \
+         docker compose down -v && docker compose up -d\n\n\
+         (-v DELETES the database, the uploaded media and the exports. There is no undo.)\n\
+         \n\
+         If you DO have data: restore the old password into DATABASE_URL instead, or change the \
+         stored one with ALTER ROLE inside the running db container. Never reach for -v to fix a \
+         login problem on a live event."
+    );
+}
+
 pub async fn create_pool(database_url: &str) -> Result<PgPool> {
     let max_connections = std::env::var("DATABASE_MAX_CONNECTIONS")
         .ok()
         .and_then(|s| s.parse::<u32>().ok())
         .unwrap_or(DEFAULT_MAX_CONNECTIONS);
 
-    let pool = PgPoolOptions::new()
+    let pool = match PgPoolOptions::new()
         .max_connections(max_connections)
+        .acquire_timeout(ACQUIRE_TIMEOUT)
         .connect(database_url)
         .await
-        .context("failed to connect to database")?;
+    {
+        Ok(pool) => pool,
+        Err(e) => {
+            explain_auth_failure(&e);
+            return Err(e).context("failed to connect to database");
+        }
+    };
 
     sqlx::migrate!()
         .run(&pool)

backend/src/error.rs

@@ -6,10 +6,25 @@ pub enum AppError {
     BadRequest(String),
     Unauthorized(String),
     Forbidden(String),
+    /// Uploads are temporarily locked (event closed / gallery released). Distinct from
+    /// `Forbidden` so the client can tell this REVERSIBLE 403 apart from a permanent one
+    /// (banned user, quota): the queued blob is kept and retried if the host reopens,
+    /// instead of being purged like a genuinely-terminal rejection.
+    UploadsLocked(String),
     NotFound(String),
     Conflict(String),
     /// Second field: optional retry-after seconds to include in the response.
     TooManyRequests(String, Option<u64>),
+    /// Per-user storage quota exhausted. Distinct from `TooManyRequests` (rate limit) so
+    /// the client can treat it as *terminal* (413, no retry) instead of backing off and
+    /// retrying a permanently-failing upload forever.
+    QuotaExceeded(String),
+    /// The server is temporarily unable to serve this request — currently only pool
+    /// saturation. Distinct from `Internal` because it is TRANSIENT and the client should be
+    /// told so: a 500 reads as "this request is broken", while a 503 + Retry-After reads as
+    /// "come back shortly", which is what the upload queue's retry classifier needs to make
+    /// the right call. Second field: optional retry-after seconds.
+    ServiceUnavailable(String, Option<u64>),
     Internal(anyhow::Error),
 }
 
@@ -19,9 +34,14 @@ impl AppError {
             Self::BadRequest(_) => (StatusCode::BAD_REQUEST, "bad_request"),
             Self::Unauthorized(_) => (StatusCode::UNAUTHORIZED, "unauthorized"),
             Self::Forbidden(_) => (StatusCode::FORBIDDEN, "forbidden"),
+            Self::UploadsLocked(_) => (StatusCode::FORBIDDEN, "uploads_locked"),
             Self::NotFound(_) => (StatusCode::NOT_FOUND, "not_found"),
             Self::Conflict(_) => (StatusCode::CONFLICT, "conflict"),
             Self::TooManyRequests(..) => (StatusCode::TOO_MANY_REQUESTS, "too_many_requests"),
+            Self::QuotaExceeded(_) => (StatusCode::PAYLOAD_TOO_LARGE, "quota_exceeded"),
+            Self::ServiceUnavailable(..) => {
+                (StatusCode::SERVICE_UNAVAILABLE, "service_unavailable")
+            }
             Self::Internal(_) => (StatusCode::INTERNAL_SERVER_ERROR, "internal_error"),
         }
     }
@@ -31,9 +51,12 @@ impl AppError {
             Self::BadRequest(msg)
             | Self::Unauthorized(msg)
             | Self::Forbidden(msg)
+            | Self::UploadsLocked(msg)
             | Self::NotFound(msg)
             | Self::Conflict(msg) => msg.clone(),
             Self::TooManyRequests(msg, _) => msg.clone(),
+            Self::ServiceUnavailable(msg, _) => msg.clone(),
+            Self::QuotaExceeded(msg) => msg.clone(),
             Self::Internal(err) => {
                 tracing::error!("internal error: {err:#}");
                 "Ein interner Fehler ist aufgetreten.".to_string()
@@ -45,10 +68,13 @@ impl AppError {
 impl IntoResponse for AppError {
     fn into_response(self) -> Response {
         let (status, code) = self.status_and_code();
-        let retry_after_secs = if let Self::TooManyRequests(_, Some(secs)) = &self {
-            Some(*secs)
-        } else {
-            None
+        // BOTH retry-carrying variants must be matched here. `message()` would fail to
+        // compile on a missing arm; this one would not — it would silently drop the header and
+        // the `retry_after_secs` body field, which is exactly the sort of omission that only
+        // shows up under the load the 503 exists for.
+        let retry_after_secs = match &self {
+            Self::TooManyRequests(_, secs) | Self::ServiceUnavailable(_, secs) => *secs,
+            _ => None,
         };
         let message = self.message();
 
@@ -62,10 +88,11 @@ impl IntoResponse for AppError {
         }
 
         let mut resp = (status, axum::Json(body)).into_response();
-        if let Some(secs) = retry_after_secs {
-            if let Ok(val) = axum::http::HeaderValue::from_str(&secs.to_string()) {
-                resp.headers_mut().insert(axum::http::header::RETRY_AFTER, val);
-            }
+        if let Some(secs) = retry_after_secs
+            && let Ok(val) = axum::http::HeaderValue::from_str(&secs.to_string())
+        {
+            resp.headers_mut()
+                .insert(axum::http::header::RETRY_AFTER, val);
         }
         resp
     }
@@ -79,6 +106,84 @@ impl From<anyhow::Error> for AppError {
 
 impl From<sqlx::Error> for AppError {
     fn from(err: sqlx::Error) -> Self {
-        Self::Internal(err.into())
+        match err {
+            // Pool saturation is load, not a bug. Reporting it as a 500 was actively harmful:
+            // the frontend's upload-queue classifier treats 5xx as transient and retries, so
+            // the retries piled straight back into the saturated pool with no Retry-After to
+            // pace them. A 503 says the same thing honestly and carries the backoff.
+            //
+            // `PoolClosed` stays `Internal` — it only happens during shutdown, where a 503
+            // would invite a retry against a server that is going away.
+            sqlx::Error::PoolTimedOut => {
+                tracing::warn!("database pool exhausted; shedding a request with 503");
+                Self::ServiceUnavailable(
+                    "Server ist gerade ausgelastet. Bitte versuche es in ein paar Sekunden erneut."
+                        .into(),
+                    Some(POOL_TIMEOUT_RETRY_AFTER_SECS),
+                )
+            }
+            other => Self::Internal(other.into()),
+        }
+    }
+}
+
+/// Retry-After for a shed request. Short: pool saturation clears in seconds once the queue
+/// drains, and a long value would make a brief spike feel like an outage.
+const POOL_TIMEOUT_RETRY_AFTER_SECS: u64 = 3;
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// `into_response` extracts `retry_after_secs` by MATCHING ON VARIANTS, so unlike
+    /// `message()` a missing arm is not a compile error — it silently drops the header. Pin the
+    /// behaviour for both retry-carrying variants.
+    #[test]
+    fn both_retry_carrying_variants_emit_retry_after() {
+        for err in [
+            AppError::TooManyRequests("slow down".into(), Some(42)),
+            AppError::ServiceUnavailable("busy".into(), Some(3)),
+        ] {
+            let expected = match &err {
+                AppError::TooManyRequests(_, Some(s)) | AppError::ServiceUnavailable(_, Some(s)) => {
+                    s.to_string()
+                }
+                _ => unreachable!(),
+            };
+            let resp = err.into_response();
+            assert_eq!(
+                resp.headers()
+                    .get(axum::http::header::RETRY_AFTER)
+                    .and_then(|v| v.to_str().ok()),
+                Some(expected.as_str()),
+                "a shed/throttled client must be told when to come back"
+            );
+        }
+    }
+
+    /// Pool saturation is load, not a bug. A 500 makes the frontend's retry classifier pile
+    /// straight back into the saturated pool with no backoff to pace it.
+    #[test]
+    fn pool_exhaustion_sheds_with_503_but_shutdown_does_not() {
+        let shed: AppError = sqlx::Error::PoolTimedOut.into();
+        assert_eq!(
+            shed.status_and_code(),
+            (StatusCode::SERVICE_UNAVAILABLE, "service_unavailable")
+        );
+
+        // PoolClosed only happens during shutdown; a 503 there would invite a retry against a
+        // server that is going away.
+        let closing: AppError = sqlx::Error::PoolClosed.into();
+        assert_eq!(
+            closing.status_and_code(),
+            (StatusCode::INTERNAL_SERVER_ERROR, "internal_error")
+        );
+
+        // Everything else must keep its existing mapping.
+        let missing: AppError = sqlx::Error::RowNotFound.into();
+        assert_eq!(
+            missing.status_and_code(),
+            (StatusCode::INTERNAL_SERVER_ERROR, "internal_error")
+        );
     }
 }

backend/src/handlers/admin.rs

@@ -1,16 +1,15 @@
 use std::collections::HashMap;
 use std::time::Duration;
 
-use axum::extract::{Query, State};
-use axum::http::{HeaderMap, StatusCode};
 use axum::Json;
+use axum::extract::{Query, State};
+use axum::http::StatusCode;
 use serde::{Deserialize, Serialize};
-use sysinfo::System;
+use uuid::Uuid;
 
 use crate::auth::middleware::RequireAdmin;
 use crate::error::AppError;
 use crate::services::config;
-use crate::services::rate_limiter::client_ip;
 use crate::state::AppState;
 
 // ── DTOs ─────────────────────────────────────────────────────────────────────
@@ -46,19 +45,17 @@ pub async fn get_stats(
         .await?
         .ok_or_else(|| AppError::NotFound("Event nicht gefunden.".into()))?;
 
-    let (user_count,): (i64,) =
-        sqlx::query_as("SELECT COUNT(*) FROM \"user\" WHERE event_id = $1")
+    let (user_count,): (i64,) = sqlx::query_as("SELECT COUNT(*) FROM \"user\" WHERE event_id = $1")
+        .bind(event.id)
+        .fetch_one(&state.pool)
+        .await?;
+
+    let (upload_count,): (i64,) =
+        sqlx::query_as("SELECT COUNT(*) FROM upload WHERE event_id = $1 AND deleted_at IS NULL")
             .bind(event.id)
             .fetch_one(&state.pool)
             .await?;
 
-    let (upload_count,): (i64,) = sqlx::query_as(
-        "SELECT COUNT(*) FROM upload WHERE event_id = $1 AND deleted_at IS NULL",
-    )
-    .bind(event.id)
-    .fetch_one(&state.pool)
-    .await?;
-
     let (comment_count,): (i64,) = sqlx::query_as(
         "SELECT COUNT(*) FROM comment c
          JOIN upload u ON u.id = c.upload_id
@@ -68,23 +65,12 @@ pub async fn get_stats(
     .fetch_one(&state.pool)
     .await?;
 
-    // Disk usage via sysinfo
-    let mut sys = System::new();
-    sys.refresh_all();
-
-    let media_path = state.config.media_path.to_string_lossy().to_string();
-    let (disk_total, disk_free) = sysinfo::Disks::new_with_refreshed_list()
-        .iter()
-        .find(|d| media_path.starts_with(d.mount_point().to_string_lossy().as_ref()))
-        .map(|d| (d.total_space(), d.available_space()))
-        .unwrap_or_else(|| {
-            // Fall back to the root disk
-            sysinfo::Disks::new_with_refreshed_list()
-                .iter()
-                .find(|d| d.mount_point().to_string_lossy() == "/")
-                .map(|d| (d.total_space(), d.available_space()))
-                .unwrap_or((0, 0))
-        });
+    // Disk usage from the shared cache (unknown mount → zeros, same as before).
+    let (disk_total, disk_free) = state
+        .disk_cache
+        .snapshot(&state.config.media_path)
+        .map(|d| (d.total, d.free))
+        .unwrap_or((0, 0));
 
     let disk_used = disk_total.saturating_sub(disk_free);
 
@@ -102,14 +88,17 @@ pub async fn get_config(
     State(state): State<AppState>,
     RequireAdmin(_auth): RequireAdmin,
 ) -> Result<Json<HashMap<String, String>>, AppError> {
-    let rows: Vec<(String, String)> =
-        sqlx::query_as("SELECT key, value FROM config ORDER BY key")
-            .fetch_all(&state.pool)
-            .await?;
+    let rows: Vec<(String, String)> = sqlx::query_as("SELECT key, value FROM config ORDER BY key")
+        .fetch_all(&state.pool)
+        .await?;
 
     Ok(Json(rows.into_iter().collect()))
 }
 
+/// Documents the wire shape of `PATCH /admin/config` (a flat `{key: value}` object).
+/// `patch_config` extracts the `HashMap` directly rather than going through this newtype, so it is
+/// never constructed in Rust — it stays as the serde-derived description of the request body.
+#[allow(dead_code)]
 #[derive(Deserialize)]
 pub struct PatchConfigRequest(pub HashMap<String, String>);
 
@@ -131,6 +120,16 @@ pub async fn patch_config(
         ("upload_rate_per_hour", true, 1.0, 100_000.0),
         ("feed_rate_per_min", true, 1.0, 100_000.0),
         ("export_rate_per_day", true, 1.0, 100_000.0),
+        // Loose per-IP ceiling on /join. The real anti-spam bucket is per (ip, name); this
+        // only bounds raw volume from one source, so it must stay well above the size of a
+        // party arriving at once (see migration 017).
+        ("join_ip_rate_per_min", true, 1.0, 100_000.0),
+        // Same shape for /recover: the per-(ip, name) bucket is the anti-guessing control,
+        // this only bounds a name-cycling flood in front of a cost-12 bcrypt (migration 019).
+        ("recover_ip_rate_per_min", true, 1.0, 100_000.0),
+        // Aggregate ceiling on likes + comments + comment deletions, per user per minute.
+        // These were the only mutating endpoints with no limit at all (migration 020).
+        ("social_rate_per_min", true, 1.0, 100_000.0),
         ("quota_tolerance", false, 0.0, 1.0),
         ("estimated_guest_count", true, 1.0, 1_000_000.0),
     ];
@@ -140,14 +139,37 @@ pub async fn patch_config(
         "feed_rate_enabled",
         "export_rate_enabled",
         "join_rate_enabled",
+        // These two per-area rate toggles are HONOURED by their handlers (auth/handlers.rs reads
+        // `admin_login_rate_enabled` and `recover_rate_enabled`, both defaulting true) but were
+        // missing from this allowlist — so the switch existed in code and could never be flipped.
+        "admin_login_rate_enabled",
+        "recover_rate_enabled",
+        "social_rate_enabled",
         "quota_enabled",
         "storage_quota_enabled",
         "upload_count_quota_enabled",
     ];
-    const TEXT_KEYS: &[&str] = &["privacy_note"];
+    const TEXT_KEYS: &[&str] = &[
+        "privacy_note",
+        "theme_preset",
+        "theme_primary",
+        "theme_accent",
+    ];
     const PRIVACY_NOTE_MAX_LEN: usize = 16 * 1024; // 16 KiB free text is plenty
+    // Preset ids the frontend knows how to render (mirror of PRESETS in
+    // frontend/src/lib/theme/palette.ts). "custom" means "use the theme_primary/accent
+    // seeds verbatim". Kept in sync by hand — a new preset must be added in both places.
+    const THEME_PRESETS: &[&str] = &[
+        "champagne-gold",
+        "rose",
+        "sage",
+        "dusk-blue",
+        "classic-silver",
+        "custom",
+    ];
 
     let mut privacy_note_changed = false;
+    let mut theme_changed = false;
 
     // Validate every key first so a bad value in the batch can't leave a partial
     // update behind — validation must fully precede any write.
@@ -162,7 +184,7 @@ pub async fn patch_config(
                 None => {
                     return Err(AppError::BadRequest(format!(
                         "Ungültiger Wert für {key}: muss eine Zahl sein."
-                    )))
+                    )));
                 }
             };
             if integer_only && n.fract() != 0.0 {
@@ -175,6 +197,23 @@ pub async fn patch_config(
                     "Wert für {key} liegt außerhalb des zulässigen Bereichs ({min}–{max})."
                 )));
             }
+            // Zero is in range and catastrophic. `quota_tolerance` is the multiplier in
+            // `free_disk * tolerance / active_uploaders`, so 0 makes every per-user limit 0 and
+            // refuses EVERY upload — mid-event, with "Du hast dein Upload-Limit für dieses Event
+            // erreicht", an error naming the wrong cause entirely. `storage_quota_enabled` is the
+            // intended off-switch.
+            //
+            // Rejecting the value rather than raising the floor: very small tolerances are
+            // legitimate (they are how a large disk is throttled down to a sensible per-guest
+            // ceiling, and how the e2e quota tests steer it — around 1e-5 on a 174 GB volume), so
+            // a floor of, say, 0.01 would forbid real configurations to prevent one typo.
+            if key_str == "quota_tolerance" && n == 0.0 {
+                return Err(AppError::BadRequest(
+                    "quota_tolerance = 0 würde jeden Upload blockieren. Zum Abschalten der \
+                     Speicher-Quote stattdessen „Speicher-Quote aktiv“ ausschalten."
+                        .into(),
+                ));
+            }
         } else if BOOL_KEYS.contains(&key_str) {
             match value.trim().to_ascii_lowercase().as_str() {
                 "true" | "false" | "1" | "0" | "yes" | "no" | "on" | "off" => {}
@@ -192,8 +231,23 @@ pub async fn patch_config(
                     "Wert für {key} ist zu lang (max. {PRIVACY_NOTE_MAX_LEN} Zeichen)."
                 )));
             }
-            if key_str == "privacy_note" {
-                privacy_note_changed = true;
+            match key_str {
+                "privacy_note" => privacy_note_changed = true,
+                "theme_preset" => {
+                    if !THEME_PRESETS.contains(&value.trim()) {
+                        return Err(AppError::BadRequest(format!("Ungültiges Theme: {value}.")));
+                    }
+                    theme_changed = true;
+                }
+                "theme_primary" | "theme_accent" => {
+                    if !is_hex_color(value.trim()) {
+                        return Err(AppError::BadRequest(format!(
+                            "Ungültige Farbe für {key}: muss #rrggbb sein."
+                        )));
+                    }
+                    theme_changed = true;
+                }
+                _ => {}
             }
         } else {
             return Err(AppError::BadRequest(format!(
@@ -216,18 +270,37 @@ pub async fn patch_config(
     }
     tx.commit().await?;
 
+    // The config cache must reflect this write on the very next read (tests PATCH then
+    // immediately assert the new value takes effect). Invalidate synchronously here —
+    // the TTL is only a backstop and must not be relied on for correctness.
+    state.config_cache.invalidate();
+
     // Notify all clients that a publicly-readable config value changed so their stores
     // (e.g. the privacy note in My Account) refresh without a manual reload.
-    if privacy_note_changed {
+    if privacy_note_changed || theme_changed {
+        let mut keys: Vec<&str> = Vec::new();
+        if privacy_note_changed {
+            keys.push("privacy_note");
+        }
+        if theme_changed {
+            keys.push("theme");
+        }
         let _ = state.sse_tx.send(crate::state::SseEvent::new(
             "event-updated",
-            serde_json::json!({ "keys": ["privacy_note"] }).to_string(),
+            serde_json::json!({ "keys": keys }).to_string(),
         ));
     }
 
     Ok(StatusCode::NO_CONTENT)
 }
 
+/// A strict `#rrggbb` hex-colour check (6 hex digits, leading `#`). Deliberately not
+/// accepting shorthand/`#rgba` so the value is safe to drop straight into CSS.
+fn is_hex_color(s: &str) -> bool {
+    let bytes = s.as_bytes();
+    bytes.len() == 7 && bytes[0] == b'#' && bytes[1..].iter().all(|b| b.is_ascii_hexdigit())
+}
+
 pub async fn get_export_jobs(
     State(state): State<AppState>,
     RequireAdmin(_auth): RequireAdmin,
@@ -266,72 +339,91 @@ pub async fn export_ticket(
     State(state): State<AppState>,
     auth: crate::auth::middleware::AuthUser,
 ) -> Json<serde_json::Value> {
+    // NOTE: intentionally NOT gated on `is_banned`. A banned user keeps *read* access
+    // by design (USER_JOURNEYS §10.3, FEATURES: "Can still download the export once
+    // released — Spec design choice"). The export is read-only, so it stays available
+    // to them, consistent with the read-only-ban model.
     let ticket = state.sse_tickets.issue(auth.token_hash);
     Json(serde_json::json!({ "ticket": ticket }))
 }
 
 /// Validate a download ticket (single-use) and confirm its session still exists.
-async fn authenticate_download_ticket(state: &AppState, ticket: &str) -> Result<(), AppError> {
+/// Resolve a single-use download ticket to the user who minted it. The caller needs the
+/// id to key the export rate limit per-user (see `enforce_export_rate`).
+async fn authenticate_download_ticket(state: &AppState, ticket: &str) -> Result<Uuid, AppError> {
     let token_hash = state
         .sse_tickets
         .consume(ticket)
         .ok_or_else(|| AppError::Unauthorized("Ticket ungültig oder abgelaufen.".into()))?;
-    crate::models::session::Session::find_by_token_hash(&state.pool, &token_hash)
+    let session = crate::models::session::Session::find_by_token_hash(&state.pool, &token_hash)
         .await
         .map_err(|e| AppError::Internal(e.into()))?
         .ok_or_else(|| AppError::Unauthorized("Sitzung nicht gefunden.".into()))?;
-    Ok(())
+    Ok(session.user_id)
 }
 
 pub async fn download_zip(
     State(state): State<AppState>,
     Query(q): Query<DownloadQuery>,
-    headers: HeaderMap,
 ) -> Result<axum::response::Response, AppError> {
-    authenticate_download_ticket(&state, &q.ticket).await?;
-    enforce_export_rate(&state, &headers).await?;
+    let user_id = authenticate_download_ticket(&state, &q.ticket).await?;
+    enforce_export_rate(&state, user_id).await?;
 
-    let event = crate::models::event::Event::find_by_slug(&state.pool, &state.config.event_slug)
-        .await?
-        .ok_or_else(|| AppError::NotFound("Event nicht gefunden.".into()))?;
+    let path =
+        resolve_export_file(&state, "zip", "Der ZIP-Export ist noch nicht verfügbar.").await?;
+    serve_file(path, "Gallery.zip", "application/zip").await
+}
 
-    if !event.export_zip_ready {
-        return Err(AppError::NotFound(
-            "Der ZIP-Export ist noch nicht verfügbar.".into(),
-        ));
-    }
+/// Resolve the on-disk path of the CURRENT export generation — readiness check and path lookup in
+/// ONE read, through the `export_current` view (migration 014).
+///
+/// This used to be two statements: the caller checked `event.export_zip_ready`, then this fetched
+/// `export_job.file_path`. A reopen landing between them served a keepsake that should have 404'd —
+/// the same stale-keepsake class, leaking through the read path, and it existed only because
+/// readiness was a stored copy rather than a derivation. `export_current` gives both facts from one
+/// consistent snapshot: it yields a row only when the event is released AND the job is `done` at the
+/// event's current epoch, so "is it ready" and "which file" can no longer disagree.
+async fn resolve_export_file(
+    state: &AppState,
+    export_type: &str,
+    not_ready_msg: &str,
+) -> Result<std::path::PathBuf, AppError> {
+    let file_path: Option<(Option<String>,)> = sqlx::query_as(
+        "SELECT c.file_path FROM export_current c
+         JOIN event e ON e.id = c.event_id
+         WHERE e.slug = $1 AND c.type = $2::export_type AND c.status = 'done'",
+    )
+    .bind(&state.config.event_slug)
+    .bind(export_type)
+    .fetch_optional(&state.pool)
+    .await
+    .map_err(|e| AppError::Internal(e.into()))?;
 
-    let path = state.config.export_path.join("Gallery.zip");
+    let Some((Some(rel),)) = file_path else {
+        return Err(AppError::NotFound(not_ready_msg.into()));
+    };
+
+    // `file_path` is stored as `exports/<name>`; the base dir is already `export_path`, so
+    // join only the file name (defends against any absolute/`..` content too).
+    let name = std::path::Path::new(&rel)
+        .file_name()
+        .ok_or_else(|| AppError::NotFound("Exportdatei nicht gefunden.".into()))?;
+    let path = state.config.export_path.join(name);
     if !path.exists() {
         return Err(AppError::NotFound("Exportdatei nicht gefunden.".into()));
     }
-
-    serve_file(path, "Gallery.zip", "application/zip").await
+    Ok(path)
 }
 
 pub async fn download_html(
     State(state): State<AppState>,
     Query(q): Query<DownloadQuery>,
-    headers: HeaderMap,
 ) -> Result<axum::response::Response, AppError> {
-    authenticate_download_ticket(&state, &q.ticket).await?;
-    enforce_export_rate(&state, &headers).await?;
-
-    let event = crate::models::event::Event::find_by_slug(&state.pool, &state.config.event_slug)
-        .await?
-        .ok_or_else(|| AppError::NotFound("Event nicht gefunden.".into()))?;
-
-    if !event.export_html_ready {
-        return Err(AppError::NotFound(
-            "Der HTML-Export ist noch nicht verfügbar.".into(),
-        ));
-    }
-
-    let path = state.config.export_path.join("Memories.zip");
-    if !path.exists() {
-        return Err(AppError::NotFound("Exportdatei nicht gefunden.".into()));
-    }
+    let user_id = authenticate_download_ticket(&state, &q.ticket).await?;
+    enforce_export_rate(&state, user_id).await?;
 
+    let path =
+        resolve_export_file(&state, "html", "Der HTML-Export ist noch nicht verfügbar.").await?;
     serve_file(path, "Memories.zip", "application/zip").await
 }
 
@@ -341,7 +433,7 @@ async fn serve_file(
     content_type: &str,
 ) -> Result<axum::response::Response, AppError> {
     use axum::body::Body;
-    use axum::http::{header, Response, StatusCode};
+    use axum::http::{Response, StatusCode, header};
     use tokio_util::io::ReaderStream;
 
     let file = tokio::fs::File::open(&path)
@@ -377,8 +469,24 @@ pub async fn export_status(
 
     let released = event.export_released_at.is_some();
 
-    let jobs: Vec<(String, String, i16)> = sqlx::query_as(
-        "SELECT type::text, status::text, progress_pct FROM export_job WHERE event_id = $1",
+    // ONE statement: the epoch comparison happens inside the query, against a single snapshot.
+    // Binding the epoch read by a previous statement would let a release/regeneration commit in
+    // between and yield `{released: true, zip: locked, html: locked}` — a state that never existed.
+    //
+    // Only jobs at the CURRENT epoch are reported. A row left behind by a retired generation (a
+    // worker superseded mid-run) is meaningless — surfacing its frozen `running`/77% would show a
+    // progress bar that never moves for a keepsake nobody is building. It reads as "locked" (no
+    // current job), which is exactly what it is.
+    // `error_message` is carried here, not just on the admin dashboard's job list. The host is the
+    // one who releases the keepsake and the one who owns the "Erneut versuchen" button, but this
+    // endpoint used to hand them a bare `failed` — so a fully actionable reason (notably the disk
+    // preflight's "needs X GB, Y GB free") was written to the row and then shown to nobody who
+    // could act on it. An admin-only diagnostic is not a diagnostic for the person on the spot.
+    let jobs: Vec<(String, String, i16, Option<String>)> = sqlx::query_as(
+        "SELECT j.type::text, j.status::text, j.progress_pct, j.error_message
+           FROM export_job j
+           JOIN event e ON e.id = j.event_id
+          WHERE e.id = $1 AND j.epoch = e.export_epoch",
     )
     .bind(event.id)
     .fetch_all(&state.pool)
@@ -386,11 +494,21 @@ pub async fn export_status(
 
     let job_status = |type_name: &str| {
         jobs.iter()
-            .find(|(t, _, _)| t == type_name)
-            .map(|(_, status, pct)| {
-                serde_json::json!({ "status": status, "progress_pct": pct })
+            .find(|(t, _, _, _)| t == type_name)
+            .map(|(_, status, pct, err)| {
+                serde_json::json!({
+                    "status": status,
+                    "progress_pct": pct,
+                    // Only on a failure. A stale message left on a row that has since been re-armed
+                    // would otherwise show an error next to a running progress bar.
+                    "error_message": if status == "failed" { err.clone() } else { None },
+                })
+            })
+            .unwrap_or_else(|| {
+                serde_json::json!({
+                    "status": "locked", "progress_pct": 0, "error_message": null,
+                })
             })
-            .unwrap_or_else(|| serde_json::json!({ "status": "locked", "progress_pct": 0 }))
     };
 
     Ok(Json(serde_json::json!({
@@ -403,21 +521,24 @@ pub async fn export_status(
 /// Centralised guard for the export rate limit. Same pattern as upload/feed: master
 /// switch + per-endpoint switch + numeric value, all stored in `config` and read on
 /// each request.
-async fn enforce_export_rate(state: &AppState, headers: &HeaderMap) -> Result<(), AppError> {
-    let rate_limits_on = config::get_bool(&state.pool, "rate_limits_enabled", true).await;
-    let export_rate_on = config::get_bool(&state.pool, "export_rate_enabled", true).await;
+async fn enforce_export_rate(state: &AppState, user_id: Uuid) -> Result<(), AppError> {
+    let rate_limits_on = config::get_bool(&state.config_cache, "rate_limits_enabled", true).await;
+    let export_rate_on = config::get_bool(&state.config_cache, "export_rate_enabled", true).await;
     if !(rate_limits_on && export_rate_on) {
         return Ok(());
     }
-    let ip = client_ip(headers, "unknown");
-    let limit = config::get_usize(&state.pool, "export_rate_per_day", 3).await;
-    if !state
-        .rate_limiter
-        .check(format!("export:{ip}"), limit, Duration::from_secs(86400))
-    {
+    let limit = config::get_usize(&state.config_cache, "export_rate_per_day", 3).await;
+    // Keyed per-user. This was the worst of the IP-keyed limiters: 3 downloads per DAY
+    // shared across every guest behind the venue's public IP, so the fourth person to
+    // fetch their keepsake was locked out until the next day.
+    if let Err(retry_after_secs) = state.rate_limiter.check_with_retry(
+        format!("export:{user_id}"),
+        limit,
+        Duration::from_secs(86400),
+    ) {
         return Err(AppError::TooManyRequests(
             "Zu viele Anfragen. Bitte warte kurz und versuche es erneut.".into(),
-            None,
+            Some(retry_after_secs),
         ));
     }
     Ok(())

backend/src/handlers/feed.rs

@@ -1,8 +1,7 @@
 use std::time::Duration;
 
-use axum::extract::{Query, State};
-use axum::http::HeaderMap;
 use axum::Json;
+use axum::extract::{Query, State};
 use chrono::{DateTime, Utc};
 use serde::{Deserialize, Serialize};
 use uuid::Uuid;
@@ -10,7 +9,6 @@ use uuid::Uuid;
 use crate::auth::middleware::AuthUser;
 use crate::error::AppError;
 use crate::services::config;
-use crate::services::rate_limiter::client_ip;
 use crate::state::AppState;
 
 #[derive(Deserialize)]
@@ -27,6 +25,8 @@ pub struct FeedUpload {
     pub uploader_name: String,
     pub preview_url: Option<String>,
     pub thumbnail_url: Option<String>,
+    /// Big-screen (~2048px) variant for the diashow. Absent until the derivative exists.
+    pub display_url: Option<String>,
     pub mime_type: String,
     pub caption: Option<String>,
     pub like_count: i64,
@@ -48,6 +48,7 @@ struct FeedRow {
     uploader_name: String,
     preview_path: Option<String>,
     thumbnail_path: Option<String>,
+    display_path: Option<String>,
     mime_type: String,
     caption: Option<String>,
     like_count: i64,
@@ -58,21 +59,23 @@ struct FeedRow {
 pub async fn feed(
     State(state): State<AppState>,
     auth: AuthUser,
-    headers: HeaderMap,
     Query(q): Query<FeedQuery>,
 ) -> Result<Json<FeedResponse>, AppError> {
-    let ip = client_ip(&headers, "unknown");
-    let rate_limits_on = config::get_bool(&state.pool, "rate_limits_enabled", true).await;
-    let feed_rate_on = config::get_bool(&state.pool, "feed_rate_enabled", true).await;
+    let rate_limits_on = config::get_bool(&state.config_cache, "rate_limits_enabled", true).await;
+    let feed_rate_on = config::get_bool(&state.config_cache, "feed_rate_enabled", true).await;
     if rate_limits_on && feed_rate_on {
-        let rate_limit = config::get_usize(&state.pool, "feed_rate_per_min", 60).await;
-        if !state
-            .rate_limiter
-            .check(format!("feed:{ip}"), rate_limit, Duration::from_secs(60))
-        {
+        let rate_limit = config::get_usize(&state.config_cache, "feed_rate_per_min", 60).await;
+        // Keyed per-user, exactly like `feed_delta` below: at a venue every guest shares
+        // one public IP, so an IP key gave the whole party a single 60/min bucket and the
+        // fastest scroller starved everyone else.
+        if let Err(retry_after_secs) = state.rate_limiter.check_with_retry(
+            format!("feed:{}", auth.user_id),
+            rate_limit,
+            Duration::from_secs(60),
+        ) {
             return Err(AppError::TooManyRequests(
                 "Zu viele Anfragen. Bitte warte kurz und versuche es erneut.".into(),
-                None,
+                Some(retry_after_secs),
             ));
         }
     }
@@ -94,7 +97,8 @@ pub async fn feed(
         let tag = hashtag.trim().trim_start_matches('#').to_lowercase();
         sqlx::query_as::<_, FeedRow>(
             "SELECT v.id, v.user_id, v.uploader_name, v.preview_path, v.thumbnail_path,
-                    v.mime_type, v.caption, v.like_count, v.comment_count, v.created_at
+                    v.display_path, v.mime_type, v.caption, v.like_count, v.comment_count,
+                    v.created_at
              FROM v_feed v
              JOIN upload_hashtag uh ON uh.upload_id = v.id
              JOIN hashtag h ON h.id = uh.hashtag_id AND h.tag = $1
@@ -113,7 +117,7 @@ pub async fn feed(
     } else {
         sqlx::query_as::<_, FeedRow>(
             "SELECT id, user_id, uploader_name, preview_path, thumbnail_path,
-                    mime_type, caption, like_count, comment_count, created_at
+                    display_path, mime_type, caption, like_count, comment_count, created_at
              FROM v_feed
              WHERE event_id = $1
                AND ($2::timestamptz IS NULL OR (created_at, id) < ($2, $3))
@@ -130,7 +134,11 @@ pub async fn feed(
 
     let has_more = rows.len() as i64 > limit;
     let rows: Vec<FeedRow> = rows.into_iter().take(limit as usize).collect();
-    let next_cursor = if has_more { rows.last().map(|r| r.id) } else { None };
+    let next_cursor = if has_more {
+        rows.last().map(|r| r.id)
+    } else {
+        None
+    };
 
     // Batch check which uploads the current user has liked
     let upload_ids: Vec<Uuid> = rows.iter().map(|r| r.id).collect();
@@ -139,8 +147,21 @@ pub async fn feed(
     let uploads = rows
         .into_iter()
         .map(|r| {
-            let preview_url = r.preview_path.map(|p| format!("/media/{p}"));
-            let thumbnail_url = r.thumbnail_path.map(|p| format!("/media/{p}"));
+            // Gated media aliases (visibility-checked, direct /media blocked). Emit the
+            // URL only when the variant actually exists — the URL is what signals the
+            // client which variant to load.
+            let preview_url = r
+                .preview_path
+                .as_ref()
+                .map(|_| format!("/api/v1/upload/{}/preview", r.id));
+            let thumbnail_url = r
+                .thumbnail_path
+                .as_ref()
+                .map(|_| format!("/api/v1/upload/{}/thumbnail", r.id));
+            let display_url = r
+                .display_path
+                .as_ref()
+                .map(|_| format!("/api/v1/upload/{}/display", r.id));
             FeedUpload {
                 liked_by_me: liked_set.contains(&r.id),
                 id: r.id,
@@ -148,6 +169,7 @@ pub async fn feed(
                 uploader_name: r.uploader_name,
                 preview_url,
                 thumbnail_url,
+                display_url,
                 mime_type: r.mime_type,
                 caption: r.caption,
                 like_count: r.like_count,
@@ -172,11 +194,22 @@ pub struct DeltaQuery {
 pub struct DeltaResponse {
     pub uploads: Vec<FeedUpload>,
     pub deleted_ids: Vec<Uuid>,
+    /// Users whose uploads became hidden (banned / uploads_hidden) since `since`. A ban is
+    /// not a soft-delete, so it never appears in `deleted_ids`; without this, a client that
+    /// missed the ephemeral `user-hidden` SSE (a reconnecting projector, most acutely) would
+    /// keep displaying the banned user's already-loaded slides. The client evicts every
+    /// upload from these users on receipt.
+    pub hidden_user_ids: Vec<Uuid>,
     /// True when the upload query hit `DELTA_LIMIT`: the response carries only the
     /// newest slice of the gap, so the client must fall back to a full feed refresh
     /// rather than merging (the older missed uploads are absent and unrecoverable
     /// via a later delta, which advances `since` past them).
     pub truncated: bool,
+    /// The server's clock at the moment this delta was computed. The client advances its
+    /// reconnect cursor from THIS, never `new Date()` — a browser clock even seconds fast
+    /// would otherwise silently skip uploads whose server `created_at` falls in the skew
+    /// window (they'd never reappear without a hard refresh).
+    pub server_time: DateTime<Utc>,
 }
 
 pub async fn feed_delta(
@@ -184,15 +217,48 @@ pub async fn feed_delta(
     auth: AuthUser,
     Query(q): Query<DeltaQuery>,
 ) -> Result<Json<DeltaResponse>, AppError> {
+    // Rate-limit the delta the same way as the paginated feed. Without this, ~100 clients
+    // reconnecting at once (post-outage, or a flapping network) each fire an unbounded
+    // delta fetch — a reconnect stampede. Keyed per-user so one client can't starve others
+    // behind a shared NAT.
+    let rate_limits_on = config::get_bool(&state.config_cache, "rate_limits_enabled", true).await;
+    let feed_rate_on = config::get_bool(&state.config_cache, "feed_rate_enabled", true).await;
+    if rate_limits_on && feed_rate_on {
+        let rate_limit = config::get_usize(&state.config_cache, "feed_rate_per_min", 60).await;
+        if let Err(retry_after_secs) = state.rate_limiter.check_with_retry(
+            format!("feed_delta:{}", auth.user_id),
+            rate_limit,
+            Duration::from_secs(60),
+        ) {
+            return Err(AppError::TooManyRequests(
+                "Zu viele Anfragen. Bitte warte kurz und versuche es erneut.".into(),
+                Some(retry_after_secs),
+            ));
+        }
+    }
+
+    // Anchor the next cursor to the DB clock, captured *before* the queries so an upload
+    // committed during this handler is re-fetched next time rather than skipped (a
+    // duplicate id merges idempotently on the client; a miss is unrecoverable).
+    let server_time: DateTime<Utc> = sqlx::query_scalar("SELECT NOW()")
+        .fetch_one(&state.pool)
+        .await?;
+
     // Bounded like the paginated feed: a stale `since` could otherwise pull the
     // entire event's uploads in one response. If a client hits the cap it should
     // fall back to a full feed refresh rather than another delta.
     const DELTA_LIMIT: i64 = 200;
+    // `>= since` (not `>`): `created_at` is not unique, so a strict `>` anchored to the exact
+    // timestamp of the last-seen upload silently drops a SECOND upload committed in the same
+    // microsecond — an unrecoverable live-update miss. `>=` re-includes the boundary rows;
+    // the client merges by id (see the feed-delta handler's `seen` set), so the duplicate is
+    // harmless while the tied upload is no longer lost. The cursor still advances to the
+    // response's `server_time`, so this doesn't re-fetch on every subsequent delta.
     let rows = sqlx::query_as::<_, FeedRow>(
         "SELECT id, user_id, uploader_name, preview_path, thumbnail_path,
-                mime_type, caption, like_count, comment_count, created_at
+                display_path, mime_type, caption, like_count, comment_count, created_at
          FROM v_feed
-         WHERE event_id = $1 AND created_at > $2
+         WHERE event_id = $1 AND created_at >= $2
          ORDER BY created_at DESC, id DESC
          LIMIT $3",
     )
@@ -206,9 +272,23 @@ pub async fn feed_delta(
     // client to full-refresh instead of merging a partial delta.
     let truncated = rows.len() as i64 >= DELTA_LIMIT;
 
+    // `>=` for the same tie-break reason as the uploads query above; re-signalling an
+    // already-removed id is idempotent on the client (it filters its list by these ids).
     let deleted_ids: Vec<(Uuid,)> = sqlx::query_as(
         "SELECT id FROM upload
-         WHERE event_id = $1 AND deleted_at IS NOT NULL AND deleted_at > $2",
+         WHERE event_id = $1 AND deleted_at IS NOT NULL AND deleted_at >= $2",
+    )
+    .bind(auth.event_id)
+    .bind(q.since)
+    .fetch_all(&state.pool)
+    .await?;
+
+    // Users hidden since the cursor (ban / uploads_hidden). Uncapped like `deleted_ids` and
+    // for the same reason — an eviction the client misses is unrecoverable via a later delta.
+    let hidden_user_ids: Vec<(Uuid,)> = sqlx::query_as(
+        "SELECT id FROM \"user\"
+         WHERE event_id = $1 AND uploads_hidden = TRUE
+           AND uploads_hidden_at IS NOT NULL AND uploads_hidden_at >= $2",
     )
     .bind(auth.event_id)
     .bind(q.since)
@@ -225,8 +305,18 @@ pub async fn feed_delta(
             id: r.id,
             user_id: r.user_id,
             uploader_name: r.uploader_name,
-            preview_url: r.preview_path.map(|p| format!("/media/{p}")),
-            thumbnail_url: r.thumbnail_path.map(|p| format!("/media/{p}")),
+            preview_url: r
+                .preview_path
+                .as_ref()
+                .map(|_| format!("/api/v1/upload/{}/preview", r.id)),
+            thumbnail_url: r
+                .thumbnail_path
+                .as_ref()
+                .map(|_| format!("/api/v1/upload/{}/thumbnail", r.id)),
+            display_url: r
+                .display_path
+                .as_ref()
+                .map(|_| format!("/api/v1/upload/{}/display", r.id)),
             mime_type: r.mime_type,
             caption: r.caption,
             like_count: r.like_count,
@@ -238,7 +328,9 @@ pub async fn feed_delta(
     Ok(Json(DeltaResponse {
         uploads,
         deleted_ids: deleted_ids.into_iter().map(|r| r.0).collect(),
+        hidden_user_ids: hidden_user_ids.into_iter().map(|r| r.0).collect(),
         truncated,
+        server_time,
     }))
 }
 
@@ -252,12 +344,11 @@ pub async fn hashtags(
     State(state): State<AppState>,
     auth: AuthUser,
 ) -> Result<Json<Vec<HashtagCount>>, AppError> {
-    let rows: Vec<(String, i64)> = sqlx::query_as(
-        "SELECT tag, upload_count FROM v_hashtag_counts WHERE event_id = $1",
-    )
-    .bind(auth.event_id)
-    .fetch_all(&state.pool)
-    .await?;
+    let rows: Vec<(String, i64)> =
+        sqlx::query_as("SELECT tag, upload_count FROM v_hashtag_counts WHERE event_id = $1")
+            .bind(auth.event_id)
+            .fetch_all(&state.pool)
+            .await?;
 
     Ok(Json(
         rows.into_iter()
@@ -287,14 +378,13 @@ async fn get_liked_set(
     if upload_ids.is_empty() {
         return std::collections::HashSet::new();
     }
-    let rows: Vec<(Uuid,)> = sqlx::query_as(
-        "SELECT upload_id FROM \"like\" WHERE user_id = $1 AND upload_id = ANY($2)",
-    )
-    .bind(user_id)
-    .bind(upload_ids)
-    .fetch_all(pool)
-    .await
-    .unwrap_or_default();
+    let rows: Vec<(Uuid,)> =
+        sqlx::query_as("SELECT upload_id FROM \"like\" WHERE user_id = $1 AND upload_id = ANY($2)")
+            .bind(user_id)
+            .bind(upload_ids)
+            .fetch_all(pool)
+            .await
+            .unwrap_or_default();
 
     rows.into_iter().map(|r| r.0).collect()
 }

backend/src/handlers/health.rs

@@ -0,0 +1,43 @@
+use std::time::Duration;
+
+use axum::extract::State;
+use axum::http::StatusCode;
+
+use crate::state::AppState;
+
+/// How long a readiness probe waits for the database before calling the app not-ready.
+///
+/// Deliberately shorter than the pool's own `acquire_timeout`: a saturated pool IS a
+/// not-ready condition, and reporting it as such is the point. Do not "fix" the two to
+/// match — that would make the probe wait out the very saturation it exists to surface.
+const READY_TIMEOUT: Duration = Duration::from_secs(2);
+
+/// Readiness: can this instance actually serve a request end to end?
+///
+/// Separate from `/health` (liveness) ON PURPOSE, and the compose healthcheck must keep
+/// pointing at `/health`. `caddy` declares `depends_on: app: {condition: service_healthy}`,
+/// so a DB-dependent healthcheck would turn a transient Postgres hiccup during boot into
+/// the reverse proxy refusing to start — converting a blip into a total outage. This route
+/// is for an external monitor, which should page rather than restart.
+///
+/// The gap this closes: every request path touches the database, so with a dead or
+/// saturated pool the app is useless while `/health` still answers "ok" — the disk-full
+/// endgame (media volume fills, Postgres cannot write WAL) stayed green all the way down.
+pub async fn ready(State(state): State<AppState>) -> (StatusCode, &'static str) {
+    let probe = sqlx::query_scalar::<_, i32>("SELECT 1").fetch_one(&state.pool);
+
+    match tokio::time::timeout(READY_TIMEOUT, probe).await {
+        Ok(Ok(_)) => (StatusCode::OK, "ready"),
+        Ok(Err(e)) => {
+            tracing::warn!(error = ?e, "readiness probe failed: database unreachable");
+            (StatusCode::SERVICE_UNAVAILABLE, "database unavailable")
+        }
+        Err(_) => {
+            tracing::warn!(
+                timeout_secs = READY_TIMEOUT.as_secs(),
+                "readiness probe timed out; the pool is saturated or the database is hung"
+            );
+            (StatusCode::SERVICE_UNAVAILABLE, "database timeout")
+        }
+    }
+}

backend/src/handlers/host.rs

@@ -1,6 +1,6 @@
+use axum::Json;
 use axum::extract::{Path, State};
 use axum::http::StatusCode;
-use axum::Json;
 use chrono::{DateTime, Utc};
 use serde::{Deserialize, Serialize};
 use uuid::Uuid;
@@ -9,8 +9,10 @@ use crate::auth::middleware::RequireHost;
 use crate::error::AppError;
 use crate::models::comment::Comment;
 use crate::models::event::Event;
+use crate::models::session::Session;
 use crate::models::upload::Upload;
 use crate::models::user::UserRole;
+use crate::services::export::Affects;
 use crate::state::{AppState, SseEvent};
 
 // ── DTOs ─────────────────────────────────────────────────────────────────────
@@ -33,11 +35,52 @@ pub struct EventStatus {
     pub is_active: bool,
     pub uploads_locked: bool,
     pub export_released: bool,
+    /// Free space on the volume the keepsake is written to. `None` when the mount can't be
+    /// resolved — the UI hides the widget rather than rendering a confident zero.
+    pub disk_free_bytes: Option<u64>,
+    /// What a full keepsake build would need right now (both halves).
+    pub keepsake_required_bytes: u64,
+    /// Whether the host should be warned. See [`disk_is_low`].
+    pub disk_low: bool,
 }
 
-#[derive(Deserialize)]
-pub struct BanRequest {
-    pub hide_uploads: bool,
+/// Absolute floor below which free space is worth surfacing regardless of gallery size — the
+/// threshold the README has carried on the roadmap since v1.
+const LOW_DISK_FLOOR_BYTES: u64 = 10_000_000_000;
+
+/// Is free space low enough that the host needs to know?
+///
+/// Two triggers, because a fixed threshold answers the wrong question. `postgres_data`,
+/// `media_data` and `exports_data` are all Docker named volumes on one filesystem, so a full disk
+/// does not degrade one subsystem — it stops Postgres writing and takes the event down. That is
+/// what the absolute floor is for.
+///
+/// The second trigger is the one that actually earns its place: the keepsake needs room for two
+/// gallery-sized archives, and the only moment a host can do anything about that is BEFORE they
+/// release. Warning at "you could not build the keepsake right now" turns a post-event dead end
+/// into a decision someone can still make.
+fn disk_is_low(free: u64, keepsake_required: u64) -> bool {
+    free < LOW_DISK_FLOOR_BYTES || free < keepsake_required
+}
+
+/// Count non-banned hosts/admins in the event OTHER than `excluding` — the operators
+/// who would remain if `excluding` were demoted or banned. Used to enforce the "an event
+/// always keeps at least one operator" floor.
+async fn remaining_operators(
+    state: &AppState,
+    event_id: Uuid,
+    excluding: Uuid,
+) -> Result<i64, AppError> {
+    let count = sqlx::query_scalar::<_, i64>(
+        "SELECT COUNT(*) FROM \"user\"
+         WHERE event_id = $1 AND id != $2
+           AND role IN ('host', 'admin') AND is_banned = FALSE",
+    )
+    .bind(event_id)
+    .bind(excluding)
+    .fetch_one(&state.pool)
+    .await?;
+    Ok(count)
 }
 
 #[derive(Deserialize)]
@@ -55,11 +98,29 @@ pub async fn get_event_status(
         .await?
         .ok_or_else(|| AppError::NotFound("Event nicht gefunden.".into()))?;
 
+    // Measured on the EXPORT volume, not the media one: that is where the cliff is, and it is a
+    // distinct mount point even when both are backed by the same filesystem. The cached reading is
+    // right here — this is advisory, polled on every dashboard load, and a 15s-stale number costs
+    // nothing (unlike the export preflight, which reads uncached because it is about to write).
+    let free = state
+        .disk_cache
+        .snapshot(&state.config.export_path)
+        .map(|d| d.free);
+    let keepsake_required_bytes =
+        crate::services::export::keepsake_space_required(&state.pool, event.id)
+            .await
+            .unwrap_or(0);
+
     Ok(Json(EventStatus {
         name: event.name,
         is_active: event.is_active,
         uploads_locked: event.uploads_locked_at.is_some(),
         export_released: event.export_released_at.is_some(),
+        disk_free_bytes: free,
+        keepsake_required_bytes,
+        // Unknown free space is NOT low. Fails open, exactly as the upload quota and the export
+        // preflight do: a scary banner on an unreadable mount would train the host to ignore it.
+        disk_low: free.is_some_and(|f| disk_is_low(f, keepsake_required_bytes)),
     }))
 }
 
@@ -93,11 +154,13 @@ pub async fn ban_user(
     State(state): State<AppState>,
     RequireHost(auth): RequireHost,
     Path(user_id): Path<Uuid>,
-    Json(body): Json<BanRequest>,
 ) -> Result<StatusCode, AppError> {
+    // The ban request carries no body — ban always hides (no per-request options).
     // Cannot ban yourself or another host/admin
     if user_id == auth.user_id {
-        return Err(AppError::BadRequest("Du kannst dich nicht selbst sperren.".into()));
+        return Err(AppError::BadRequest(
+            "Du kannst dich nicht selbst sperren.".into(),
+        ));
     }
     let target = sqlx::query_as::<_, (String,)>(
         "SELECT role::text FROM \"user\" WHERE id = $1 AND event_id = $2",
@@ -108,33 +171,74 @@ pub async fn ban_user(
     .await?
     .ok_or_else(|| AppError::NotFound("Benutzer nicht gefunden.".into()))?;
 
-    if target.0 == "admin" || (target.0 == "host" && auth.role != crate::models::user::UserRole::Admin) {
-        return Err(AppError::Forbidden("Du kannst diesen Benutzer nicht sperren.".into()));
-    }
-
-    sqlx::query(
-        "UPDATE \"user\" SET is_banned = TRUE, uploads_hidden = $2 WHERE id = $1 AND event_id = $3",
-    )
-    .bind(user_id)
-    .bind(body.hide_uploads)
-    .bind(auth.event_id)
-    .execute(&state.pool)
-    .await?;
-
-    // If we hid their uploads, evict them live from every feed + the diashow so a
-    // banned guest's content disappears without each viewer having to reload.
-    if body.hide_uploads {
-        let _ = state.sse_tx.send(SseEvent::new(
-            "user-hidden",
-            serde_json::json!({ "user_id": user_id }).to_string(),
+    if target.0 == "admin"
+        || (target.0 == "host" && auth.role != crate::models::user::UserRole::Admin)
+    {
+        return Err(AppError::Forbidden(
+            "Du kannst diesen Benutzer nicht sperren.".into(),
         ));
     }
 
+    // Floor: never leave the event with zero operators. Banning removes the target from
+    // the active-operator pool, so refuse if they're the last non-banned host/admin.
+    if target.0 == "host" && remaining_operators(&state, auth.event_id, user_id).await? == 0 {
+        return Err(AppError::BadRequest(
+            "Der letzte Host kann nicht gesperrt werden.".into(),
+        ));
+    }
+
+    // Ban ALWAYS hides: a banned user's content is "gone" everywhere. The visibility
+    // views/queries now also filter on `is_banned` (defense in depth), and we set
+    // `uploads_hidden` so the existing `user-hidden` live-eviction path fires too. The old
+    // opt-out checkbox is gone — `hide_uploads` in the request is ignored.
+    //
+    // We deliberately do NOT revoke the banned user's sessions. This is a *read-only ban*
+    // by design (USER_JOURNEYS §10.3): the user keeps read access to the feed and can still
+    // download the released export — writes and host/admin actions are what the ban blocks
+    // (enforced live on the write handlers + Require{Host,Admin}). Revoking sessions would
+    // contradict that model, break the documented "banned guest can still download the
+    // keepsake" flow, and be ineffective anyway (the user could just /recover a new session).
+    //
+    // The ban and the keepsake invalidation are ONE transaction — see `host_delete_upload`.
+    let mut tx = state.pool.begin().await?;
+    sqlx::query(
+        "UPDATE \"user\"
+         SET is_banned = TRUE, uploads_hidden = TRUE, uploads_hidden_at = NOW()
+         WHERE id = $1 AND event_id = $2",
+    )
+    .bind(user_id)
+    .bind(auth.event_id)
+    .execute(&mut *tx)
+    .await?;
+
+    // A ban hides the user's uploads EVERYWHERE — and the keepsake is the place that matters most,
+    // because it is the copy people keep. The export already filters `is_banned = FALSE`, so a
+    // FUTURE export excludes them; without this, an ALREADY-RELEASED archive would keep serving a
+    // banned user's photos forever. Same class as a takedown, so same treatment.
+    let regen = crate::services::export::invalidate_and_arm(
+        &mut tx,
+        &state.config.event_slug,
+        Affects::Both,
+    )
+    .await?;
+    tx.commit().await?;
+    if let Some(r) = regen {
+        start_regen(&state, r);
+    }
+
+    // Evict their content live from every feed + the diashow so it disappears without
+    // each viewer having to reload. (Their own SSE stream is separately dropped by the
+    // is_banned revalidation in `sse::stream`, so they stop receiving live pushes while
+    // retaining plain read access.)
+    let _ = state.sse_tx.send(SseEvent::new(
+        "user-hidden",
+        serde_json::json!({ "user_id": user_id }).to_string(),
+    ));
+
     tracing::info!(
         actor_user_id = %auth.user_id,
         target_user_id = %user_id,
         event_id = %auth.event_id,
-        hide_uploads = body.hide_uploads,
         "host: ban_user"
     );
 
@@ -146,16 +250,56 @@ pub async fn unban_user(
     RequireHost(auth): RequireHost,
     Path(user_id): Path<Uuid>,
 ) -> Result<StatusCode, AppError> {
-    let result = sqlx::query(
-        "UPDATE \"user\" SET is_banned = FALSE WHERE id = $1 AND event_id = $2",
+    // Mirror the ban guard: a host may only lift bans on guests, never on hosts or
+    // admins. Without this a host could override an admin's ban of another host,
+    // which is asymmetric with `ban_user` and lets a host escalate a peer back in.
+    let target = sqlx::query_as::<_, (String,)>(
+        "SELECT role::text FROM \"user\" WHERE id = $1 AND event_id = $2",
     )
     .bind(user_id)
     .bind(auth.event_id)
-    .execute(&state.pool)
+    .fetch_optional(&state.pool)
+    .await?
+    .ok_or_else(|| AppError::NotFound("Benutzer nicht gefunden.".into()))?;
+
+    if target.0 == "admin"
+        || (target.0 == "host" && auth.role != crate::models::user::UserRole::Admin)
+    {
+        return Err(AppError::Forbidden(
+            "Du kannst diesen Benutzer nicht entsperren.".into(),
+        ));
+    }
+
+    // Unban restores visibility too: ban set `uploads_hidden = TRUE`, so clearing only
+    // `is_banned` would leave their content invisible. Clear all three (the timestamp too,
+    // so a future ban stamps a fresh `uploads_hidden_at` the reconnect delta will replay).
+    let mut tx = state.pool.begin().await?;
+    let result = sqlx::query(
+        "UPDATE \"user\"
+         SET is_banned = FALSE, uploads_hidden = FALSE, uploads_hidden_at = NULL
+         WHERE id = $1 AND event_id = $2",
+    )
+    .bind(user_id)
+    .bind(auth.event_id)
+    .execute(&mut *tx)
     .await?;
     if result.rows_affected() == 0 {
         return Err(AppError::NotFound("Benutzer nicht gefunden.".into()));
     }
+
+    // The mirror of the ban case: an unban RESTORES their uploads to the export query, so an
+    // already-released keepsake is now missing content it should contain. Rebuild it.
+    let regen = crate::services::export::invalidate_and_arm(
+        &mut tx,
+        &state.config.event_slug,
+        Affects::Both,
+    )
+    .await?;
+    tx.commit().await?;
+    if let Some(r) = regen {
+        start_regen(&state, r);
+    }
+
     tracing::info!(
         actor_user_id = %auth.user_id,
         target_user_id = %user_id,
@@ -165,6 +309,55 @@ pub async fn unban_user(
     Ok(StatusCode::NO_CONTENT)
 }
 
+/// Force a keepsake rebuild. The ESCAPE HATCH.
+///
+/// Without this, a failed or stranded export is terminal at runtime: `release_gallery` refuses an
+/// already-released event ("bereits freigegeben"), `recover_exports` only runs at boot, and there is
+/// no other retry path — so the host's only options were restarting the container or reopening the
+/// event (which unlocks uploads to every guest and discards the release). This is also the recovery
+/// path for a keepsake that went stale for any reason we haven't thought of.
+pub async fn rebuild_export(
+    State(state): State<AppState>,
+    RequireHost(auth): RequireHost,
+) -> Result<StatusCode, AppError> {
+    let mut tx = state.pool.begin().await?;
+    let regen = crate::services::export::invalidate_and_arm(
+        &mut tx,
+        &state.config.event_slug,
+        Affects::Both,
+    )
+    .await?;
+    tx.commit().await?;
+
+    let Some(r) = regen else {
+        return Err(AppError::BadRequest(
+            "Die Galerie ist nicht freigegeben — es gibt nichts neu zu erzeugen.".into(),
+        ));
+    };
+
+    // No debounce: this is an explicit, deliberate host action, not a burst.
+    for export_type in ["zip", "html"] {
+        let _ = state.sse_tx.send(SseEvent::new(
+            "export-progress",
+            serde_json::json!({ "type": export_type, "progress_pct": 0 }).to_string(),
+        ));
+    }
+    crate::services::export::spawn_export_jobs(
+        r.event_id,
+        r.event_name,
+        r.epoch,
+        state.config.comments_enabled,
+        std::time::Duration::ZERO,
+        state.pool.clone(),
+        state.config.media_path.clone(),
+        state.config.export_path.clone(),
+        state.sse_tx.clone(),
+    );
+
+    tracing::info!(actor_user_id = %auth.user_id, "host: rebuild_export");
+    Ok(StatusCode::NO_CONTENT)
+}
+
 pub async fn set_role(
     State(state): State<AppState>,
     RequireHost(auth): RequireHost,
@@ -182,14 +375,15 @@ pub async fn set_role(
         _ => {
             return Err(AppError::BadRequest(
                 "Ungültige Rolle. Erlaubt: guest, host.".into(),
-            ))
+            ));
         }
     };
 
-    // Look up the current role so we can apply the host-vs-admin guard. Hosts may
-    // promote guests and demote *other* hosts (the user explicitly requested this
-    // expansion). Hosts may not touch admins. Admins may do anything (except change
-    // themselves, blocked above).
+    // Look up the current role so we can apply the host-vs-admin guard. A plain host may
+    // promote/demote GUESTS only; it may not change any host's or admin's role (see the
+    // guard below — this closes the demote-a-peer-host→ban/PIN-reset takeover chain, F1).
+    // Only an admin may change a host's role. Admins may do anything except change
+    // themselves (blocked above).
     let target = sqlx::query_as::<_, (String,)>(
         "SELECT role::text FROM \"user\" WHERE id = $1 AND event_id = $2",
     )
@@ -199,9 +393,25 @@ pub async fn set_role(
     .await?
     .ok_or_else(|| AppError::NotFound("Benutzer nicht gefunden.".into()))?;
 
-    if target.0 == "admin" {
+    // Admins are untouchable by hosts. A plain host also may not demote another
+    // *host*: without this guard a host could demote a peer host to guest and then
+    // ban / PIN-reset (→ account-takeover via /recover) them — the ban/pin-reset peer
+    // guards key off the target's *current* role, so a prior demotion would launder
+    // past them. Only an admin may change a host's role.
+    if target.0 == "admin" || (target.0 == "host" && auth.role != UserRole::Admin) {
         return Err(AppError::Forbidden(
-            "Admins können nicht geändert werden.".into(),
+            "Du darfst die Rolle dieses Benutzers nicht ändern.".into(),
+        ));
+    }
+
+    // Floor: demoting the last non-banned host/admin to guest would leave the event with
+    // no operator. Refuse.
+    if new_role == "guest"
+        && target.0 == "host"
+        && remaining_operators(&state, auth.event_id, user_id).await? == 0
+    {
+        return Err(AppError::BadRequest(
+            "Der letzte Host kann nicht zum Gast gemacht werden.".into(),
         ));
     }
 
@@ -262,26 +472,41 @@ pub async fn reset_user_pin(
         _ => {
             return Err(AppError::Forbidden(
                 "Du darfst die PIN dieses Benutzers nicht zurücksetzen.".into(),
-            ))
+            ));
         }
     }
 
     let pin: String = format!("{:04}", rand::rng().random_range(0..10000u32));
-    let pin_hash =
-        bcrypt::hash(&pin, 12).map_err(|e| AppError::Internal(anyhow::anyhow!(e)))?;
+    let pin_hash = crate::auth::handlers::hash_password(pin.clone(), 12).await?;
 
     sqlx::query(
         "UPDATE \"user\"
          SET recovery_pin_hash = $1,
              failed_pin_attempts = 0,
              pin_locked_until = NULL
-         WHERE id = $2",
+         WHERE id = $2 AND event_id = $3",
     )
     .bind(&pin_hash)
     .bind(user_id)
+    .bind(auth.event_id)
     .execute(&state.pool)
     .await?;
 
+    // A PIN reset means the old credential is compromised/forgotten — revoke every
+    // existing session so old devices must re-authenticate with the new PIN. This is a
+    // security-relevant revoke: if it fails, the old sessions stay valid (sessions are
+    // token- not PIN-bound), so surface the error in logs rather than swallowing it
+    // silently while reporting success to the host.
+    if let Err(e) = Session::delete_all_for_user(&state.pool, user_id).await {
+        tracing::error!(error = ?e, user_id = %user_id, "PIN reset: failed to revoke sessions");
+    }
+
+    // Resolve any pending in-app "I forgot my PIN" request for this user.
+    let _ = sqlx::query("DELETE FROM pin_reset_request WHERE user_id = $1")
+        .bind(user_id)
+        .execute(&state.pool)
+        .await;
+
     // Notify the *recipient* device(s) if they happen to be online so they can clear
     // their cached local PIN. They'll save the new one on the next /recover.
     let _ = state.sse_tx.send(SseEvent::new(
@@ -299,6 +524,88 @@ pub async fn reset_user_pin(
     Ok(Json(PinResetResponse { pin }))
 }
 
+#[derive(Serialize, sqlx::FromRow)]
+pub struct PinResetRequestSummary {
+    pub id: Uuid,
+    pub user_id: Uuid,
+    pub display_name: String,
+    pub created_at: DateTime<Utc>,
+}
+
+/// List pending in-app PIN-reset requests so a host can action them (via the existing
+/// `reset_user_pin`, which also clears the request).
+pub async fn list_pin_reset_requests(
+    State(state): State<AppState>,
+    RequireHost(auth): RequireHost,
+) -> Result<Json<Vec<PinResetRequestSummary>>, AppError> {
+    let rows = sqlx::query_as::<_, PinResetRequestSummary>(
+        "SELECT r.id, r.user_id, u.display_name, r.created_at
+         FROM pin_reset_request r
+         JOIN \"user\" u ON u.id = r.user_id
+         WHERE r.event_id = $1
+         ORDER BY r.created_at ASC",
+    )
+    .bind(auth.event_id)
+    .fetch_all(&state.pool)
+    .await?;
+    Ok(Json(rows))
+}
+
+/// Dismiss a PIN-reset request without resetting (e.g. the host couldn't verify the
+/// requester's identity).
+pub async fn dismiss_pin_reset_request(
+    State(state): State<AppState>,
+    RequireHost(auth): RequireHost,
+    Path(id): Path<Uuid>,
+) -> Result<StatusCode, AppError> {
+    sqlx::query("DELETE FROM pin_reset_request WHERE id = $1 AND event_id = $2")
+        .bind(id)
+        .bind(auth.event_id)
+        .execute(&state.pool)
+        .await?;
+    Ok(StatusCode::NO_CONTENT)
+}
+
+/// Content changed AFTER the gallery was released — regenerate the keepsake.
+///
+/// Deleting a photo used to remove it from the live feed but leave it in the already-generated
+/// archive FOREVER: the old `if ready { continue }` skip guaranteed the export was never rebuilt.
+/// For a takedown ("please remove my photo") that is the one place it most needs to disappear.
+///
+/// Bumping the epoch (while staying released) retires the current generation, so the stale archive
+/// stops being downloadable the instant the delete commits, and a fresh worker rebuilds it without
+/// the removed content. The download 404s in the meantime, which is the correct answer — serving
+/// the old archive would serve the deleted photo.
+/// Start the workers for a regeneration that was armed inside a (now-committed) transaction, and
+/// tell every client the current keepsake just became undownloadable.
+///
+/// The SSE matters: bumping the epoch retires the archive INSTANTLY, so `/export/zip` starts 404ing
+/// the moment the change commits. Without a nudge, a guest sitting on `/export` keeps rendering an
+/// enabled "download" button for the whole rebuild. Both the nav badge and the export page already
+/// refetch `/export/status` on `export-progress`, so a 0% tick is the cheapest correct signal.
+pub fn start_regen(state: &AppState, regen: crate::services::export::PendingRegen) {
+    for export_type in ["zip", "html"] {
+        let _ = state.sse_tx.send(SseEvent::new(
+            "export-progress",
+            serde_json::json!({ "type": export_type, "progress_pct": 0 }).to_string(),
+        ));
+    }
+    crate::services::export::spawn_export_jobs(
+        regen.event_id,
+        regen.event_name,
+        regen.epoch,
+        state.config.comments_enabled,
+        // Debounced: a takedown pass is a burst, and each request retires the last generation. The
+        // delay lets superseded workers fail their claim and do zero work instead of each building
+        // a full archive. See export::REGEN_DEBOUNCE.
+        crate::services::export::REGEN_DEBOUNCE,
+        state.pool.clone(),
+        state.config.media_path.clone(),
+        state.config.export_path.clone(),
+        state.sse_tx.clone(),
+    );
+}
+
 pub async fn host_delete_upload(
     State(state): State<AppState>,
     RequireHost(auth): RequireHost,
@@ -308,15 +615,29 @@ pub async fn host_delete_upload(
         .await?
         .ok_or_else(|| AppError::NotFound("Upload nicht gefunden.".into()))?;
 
-    let deleted = Upload::soft_delete_in_event(&state.pool, upload_id, auth.event_id).await?;
+    // The delete and the keepsake invalidation are ONE transaction: if the delete committed and the
+    // invalidation didn't, the taken-down photo would stay downloadable forever and nothing would
+    // notice (the keepsake still looks complete, and the host can no longer find the upload to retry).
+    let mut tx = state.pool.begin().await?;
+    let deleted = Upload::soft_delete_in_event(&mut tx, upload_id, auth.event_id).await?;
     if !deleted {
         return Err(AppError::NotFound("Upload nicht gefunden.".into()));
     }
+    let regen = crate::services::export::invalidate_and_arm(
+        &mut tx,
+        &state.config.event_slug,
+        Affects::Both,
+    )
+    .await?;
+    tx.commit().await?;
 
     let _ = state.sse_tx.send(SseEvent::new(
         "upload-deleted",
         serde_json::json!({ "upload_id": upload.id }).to_string(),
     ));
+    if let Some(r) = regen {
+        start_regen(&state, r);
+    }
 
     tracing::info!(
         actor_user_id = %auth.user_id,
@@ -333,15 +654,29 @@ pub async fn host_delete_comment(
     RequireHost(auth): RequireHost,
     Path(comment_id): Path<Uuid>,
 ) -> Result<StatusCode, AppError> {
-    let deleted =
-        Comment::soft_delete_in_event(&state.pool, comment_id, auth.event_id).await?;
+    let mut tx = state.pool.begin().await?;
+    let deleted = Comment::soft_delete_in_event(&mut tx, comment_id, auth.event_id).await?;
     if !deleted {
         return Err(AppError::NotFound("Kommentar nicht gefunden.".into()));
     }
+    // Only the HTML viewer embeds comments — the ZIP is media-only, so it is carried forward rather
+    // than rebuilt. Otherwise moderating one comment would 404 the photo download for minutes to
+    // change nothing in it.
+    let regen = crate::services::export::invalidate_and_arm(
+        &mut tx,
+        &state.config.event_slug,
+        Affects::ViewerOnly,
+    )
+    .await?;
+    tx.commit().await?;
+
     let _ = state.sse_tx.send(SseEvent::new(
         "comment-deleted",
         serde_json::json!({ "comment_id": comment_id }).to_string(),
     ));
+    if let Some(r) = regen {
+        start_regen(&state, r);
+    }
     tracing::info!(
         actor_user_id = %auth.user_id,
         event_id = %auth.event_id,
@@ -375,8 +710,21 @@ pub async fn open_event(
     State(state): State<AppState>,
     RequireHost(_auth): RequireHost,
 ) -> Result<StatusCode, AppError> {
+    // Reopening invalidates any prior release: the keepsake was snapshotted at release time, so
+    // allowing new uploads afterwards would silently diverge the live feed from the frozen export.
+    //
+    // ONE statement retires the entire export generation. Bumping `export_epoch` in the same write
+    // that clears `export_released_at` instantly invalidates every in-flight worker, every `done`
+    // row and all readiness — because readiness is DERIVED from this epoch (migration 014), not
+    // stored. There is no export_job row to touch and nothing to keep in sync, so this needs no
+    // transaction. Any worker still streaming holds the old epoch and is now inert: its
+    // epoch-guarded finalize matches nothing, and it discards its own output.
     let result = sqlx::query(
-        "UPDATE event SET uploads_locked_at = NULL WHERE slug = $1 AND uploads_locked_at IS NOT NULL",
+        "UPDATE event
+         SET uploads_locked_at  = NULL,
+             export_released_at = NULL,
+             export_epoch       = export_epoch + 1
+         WHERE slug = $1 AND (uploads_locked_at IS NOT NULL OR export_released_at IS NOT NULL)",
     )
     .bind(&state.config.event_slug)
     .execute(&state.pool)
@@ -393,17 +741,37 @@ pub async fn release_gallery(
     State(state): State<AppState>,
     RequireHost(_auth): RequireHost,
 ) -> Result<StatusCode, AppError> {
-    // Atomic claim: the conditional UPDATE is the sole gate, so two concurrent
-    // release calls can't both pass a check-then-set and double-enqueue exports.
-    // rows_affected == 0 means someone already released.
-    let result = sqlx::query(
-        "UPDATE event SET export_released_at = NOW()
-         WHERE slug = $1 AND export_released_at IS NULL",
+    // The release claim, the epoch bump, the upload lock and BOTH job rows are written in ONE
+    // transaction. Two reasons, both of which were live bugs:
+    //
+    //  1. Cancellation. This handler used to commit `export_released_at` and only THEN await the
+    //     enqueue. Axum drops the handler future when the client disconnects (closed tab, proxy
+    //     timeout), which left the event released and uploads locked with ZERO export_job rows and
+    //     no workers: downloads 404 forever and the host cannot retry, because release_gallery
+    //     rejects an already-released event ("bereits freigegeben"). Only a restart escaped it.
+    //     Now nothing is committed until every row is written, and the workers are spawned AFTER
+    //     the commit (a detached `tokio::spawn` survives cancellation).
+    //  2. Atomicity vs. a concurrent reopen. Bumping the epoch in the same statement that sets
+    //     `export_released_at` means no worker and no reader can ever observe "released again but
+    //     the generation hasn't moved on yet" — the window every previous fix kept leaving open.
+    //
+    // Release also locks uploads in the same statement (release ⇒ lock), so the export snapshot is
+    // taken against a frozen upload set. `COALESCE` preserves an earlier explicit lock time.
+    let mut tx = state.pool.begin().await?;
+
+    let claimed: Option<(Uuid, String, i64)> = sqlx::query_as(
+        "UPDATE event
+         SET export_released_at = NOW(),
+             uploads_locked_at  = COALESCE(uploads_locked_at, NOW()),
+             export_epoch       = export_epoch + 1
+         WHERE slug = $1 AND export_released_at IS NULL
+         RETURNING id, name, export_epoch",
     )
     .bind(&state.config.event_slug)
-    .execute(&state.pool)
+    .fetch_optional(&mut *tx)
     .await?;
-    if result.rows_affected() == 0 {
+
+    let Some((event_id, event_name, epoch)) = claimed else {
         // Distinguish "no such event" from "already released" for a clean error.
         let exists = Event::find_by_slug(&state.pool, &state.config.event_slug)
             .await?
@@ -413,29 +781,26 @@ pub async fn release_gallery(
         } else {
             AppError::NotFound("Event nicht gefunden.".into())
         });
-    }
+    };
 
-    // We won the claim — load the event for its id/name to enqueue export jobs.
-    let event = Event::find_by_slug(&state.pool, &state.config.event_slug)
-        .await?
-        .ok_or_else(|| AppError::NotFound("Event nicht gefunden.".into()))?;
+    // Arm both types at THIS epoch. No "skip the type that's already ready" check any more: the
+    // epoch bump above retired every prior generation, so there is nothing to preserve and nothing
+    // to be fooled by. (That skip was how a stale ready flag used to suppress regeneration.)
+    crate::services::export::enqueue_jobs_at_epoch(&mut tx, event_id, epoch).await?;
 
-    // Enqueue export jobs
-    for export_type in ["zip", "html"] {
-        sqlx::query(
-            "INSERT INTO export_job (event_id, type) VALUES ($1, $2::export_type)
-             ON CONFLICT (event_id, type) DO NOTHING",
-        )
-        .bind(event.id)
-        .bind(export_type)
-        .execute(&state.pool)
-        .await?;
-    }
+    tx.commit().await?;
 
-    // Spawn export workers
+    // Release locks uploads too — tell any open composer to flip to the locked UI live rather than
+    // discovering it via a rejected upload.
+    let _ = state.sse_tx.send(SseEvent::new("event-closed", "{}"));
+
+    // Detached — survives this handler being cancelled.
     crate::services::export::spawn_export_jobs(
-        event.id,
-        event.name,
+        event_id,
+        event_name,
+        epoch,
+        state.config.comments_enabled,
+        std::time::Duration::ZERO,
         state.pool.clone(),
         state.config.media_path.clone(),
         state.config.export_path.clone(),
@@ -444,3 +809,45 @@ pub async fn release_gallery(
 
     Ok(StatusCode::NO_CONTENT)
 }
+
+#[cfg(test)]
+mod tests {
+    use super::{LOW_DISK_FLOOR_BYTES, disk_is_low};
+
+    const GB: u64 = 1_000_000_000;
+
+    #[test]
+    fn a_healthy_disk_with_room_for_the_keepsake_is_not_low() {
+        assert!(!disk_is_low(40 * GB, 25 * GB));
+    }
+
+    #[test]
+    fn the_absolute_floor_fires_even_when_the_gallery_is_tiny() {
+        // All three volumes share one filesystem, so running out doesn't degrade one subsystem —
+        // Postgres stops being able to write and the event goes down. A 1 GB gallery would clear
+        // the keepsake test comfortably; the floor is what catches this.
+        assert!(disk_is_low(5 * GB, GB));
+        assert!(disk_is_low(LOW_DISK_FLOOR_BYTES - 1, 0));
+        assert!(!disk_is_low(LOW_DISK_FLOOR_BYTES, 0));
+    }
+
+    #[test]
+    fn plenty_of_space_is_still_low_when_the_keepsake_would_not_fit() {
+        // THE case the fixed threshold misses, and the one that matters: 30 GB free is nowhere near
+        // any floor, but a 30 GB gallery needs room for TWO archives. The host can act on this
+        // before releasing; after releasing, they cannot.
+        assert!(disk_is_low(30 * GB, 66 * GB));
+    }
+
+    #[test]
+    fn the_keepsake_trigger_is_exact_at_the_boundary() {
+        assert!(!disk_is_low(66 * GB, 66 * GB), "exactly enough is enough");
+        assert!(disk_is_low(66 * GB - 1, 66 * GB));
+    }
+
+    #[test]
+    fn an_empty_gallery_needs_nothing_and_only_the_floor_applies() {
+        assert!(!disk_is_low(11 * GB, 0));
+        assert!(disk_is_low(9 * GB, 0));
+    }
+}

backend/src/handlers/me.rs

@@ -7,14 +7,14 @@
 //!   account page loads this once on mount instead of issuing several round trips.
 //! - `GET /api/v1/me/quota`  — live per-user storage quota estimate.
 
-use axum::extract::State;
 use axum::Json;
+use axum::extract::State;
 use serde::Serialize;
 
 use crate::auth::middleware::AuthUser;
 use crate::error::AppError;
 use crate::handlers::upload::compute_storage_quota;
-use crate::models::user::User;
+use crate::models::user::{User, UserRole};
 use crate::services::config;
 use crate::state::AppState;
 
@@ -37,12 +37,26 @@ pub async fn get_quota(
 
     let estimate = compute_storage_quota(&state).await;
 
+    // Raw server telemetry (free disk, concurrent uploader count) is staff-only — it
+    // must never reach a guest, even though the guest upload UI no longer renders it.
+    // A guest still gets their own `used`/`limit` so enforcement stays transparent to
+    // the code paths that consume it; only the server-wide fields are zeroed.
+    let is_staff = matches!(auth.role, UserRole::Host | UserRole::Admin);
+
     Ok(Json(QuotaDto {
         enabled: estimate.limit_bytes.is_some(),
         used_bytes: user.total_upload_bytes,
         limit_bytes: estimate.limit_bytes,
-        active_uploaders: estimate.active_uploaders,
-        free_disk_bytes: estimate.free_disk_bytes,
+        active_uploaders: if is_staff {
+            estimate.active_uploaders
+        } else {
+            0
+        },
+        free_disk_bytes: if is_staff {
+            estimate.free_disk_bytes
+        } else {
+            0
+        },
     }))
 }
 
@@ -55,6 +69,12 @@ pub struct MeContextDto {
     pub privacy_note: String,
     pub quota_enabled: bool,
     pub storage_quota_enabled: bool,
+    /// Uploads are locked (event closed) — the composer should show a locked state live
+    /// instead of letting a guest compose an upload only to eat a 403.
+    pub uploads_locked: bool,
+    /// The gallery has been released and the export snapshotted — uploads are permanently
+    /// closed for this run (release ⇒ lock, and reopening regenerates).
+    pub gallery_released: bool,
 }
 
 pub async fn get_context(
@@ -65,9 +85,21 @@ pub async fn get_context(
         .await?
         .ok_or_else(|| AppError::NotFound("Benutzer nicht gefunden.".into()))?;
 
-    let privacy_note = config::get_str(&state.pool, "privacy_note", "").await;
-    let quota_enabled = config::get_bool(&state.pool, "quota_enabled", true).await;
-    let storage_quota_enabled = config::get_bool(&state.pool, "storage_quota_enabled", true).await;
+    let privacy_note = config::get_str(&state.config_cache, "privacy_note", "").await;
+    let quota_enabled = config::get_bool(&state.config_cache, "quota_enabled", true).await;
+    let storage_quota_enabled =
+        config::get_bool(&state.config_cache, "storage_quota_enabled", true).await;
+
+    let event =
+        crate::models::event::Event::find_by_slug(&state.pool, &state.config.event_slug).await?;
+    let uploads_locked = event
+        .as_ref()
+        .map(|e| e.uploads_locked_at.is_some())
+        .unwrap_or(false);
+    let gallery_released = event
+        .as_ref()
+        .map(|e| e.export_released_at.is_some())
+        .unwrap_or(false);
 
     Ok(Json(MeContextDto {
         user_id: user.id,
@@ -76,5 +108,7 @@ pub async fn get_context(
         privacy_note,
         quota_enabled,
         storage_quota_enabled,
+        uploads_locked,
+        gallery_released,
     }))
 }

backend/src/handlers/mod.rs

@@ -1,7 +1,9 @@
 pub mod admin;
 pub mod feed;
+pub mod health;
 pub mod host;
 pub mod me;
+pub mod public;
 pub mod social;
 pub mod sse;
 pub mod test_admin;

backend/src/handlers/public.rs

@@ -0,0 +1,44 @@
+//! Unauthenticated, read-only endpoints safe to expose before a user has joined.
+
+use axum::Json;
+use axum::extract::State;
+use serde::Serialize;
+
+use crate::services::config;
+use crate::state::AppState;
+
+#[derive(Serialize)]
+pub struct PublicEventDto {
+    pub name: String,
+    pub slug: String,
+    /// Whether the comment feature is on (env `COMMENTS_ENABLED`). The frontend hides
+    /// the whole comment UI when false; exposed here so even the pre-auth shell knows.
+    pub comments_enabled: bool,
+    /// Active colour theme. `preset` is an id the frontend maps to a palette (or
+    /// "custom"); `primary`/`accent` are the `#rrggbb` seeds the ramps derive from.
+    /// Resolved as DB-config override → env default. Public so the theme applies on
+    /// the very first (pre-auth) paint without a flash.
+    pub theme_preset: String,
+    pub theme_primary: String,
+    pub theme_accent: String,
+}
+
+/// Public event identity + presentation config, used by the pre-auth join/recover
+/// screens (which event am I joining, what does it look like). Only non-user-scoped
+/// fields are exposed, so this is safe without a token. Identity comes straight from
+/// instance config; the theme is resolved from the runtime `config` table (admin UI)
+/// falling back to the env-seeded default.
+pub async fn get_public_event(State(state): State<AppState>) -> Json<PublicEventDto> {
+    let cache = &state.config_cache;
+    Json(PublicEventDto {
+        name: state.config.event_name.clone(),
+        slug: state.config.event_slug.clone(),
+        comments_enabled: state.config.comments_enabled,
+        theme_preset: config::get_str(cache, "theme_preset", &state.config.default_theme_preset)
+            .await,
+        theme_primary: config::get_str(cache, "theme_primary", &state.config.default_theme_primary)
+            .await,
+        theme_accent: config::get_str(cache, "theme_accent", &state.config.default_theme_accent)
+            .await,
+    })
+}

backend/src/handlers/social.rs

@@ -1,8 +1,8 @@
+use axum::Json;
 use axum::extract::{Path, Query, State};
 use axum::http::StatusCode;
-use axum::Json;
 use chrono::{DateTime, Utc};
-use serde::Deserialize;
+use serde::{Deserialize, Serialize};
 use uuid::Uuid;
 
 use crate::auth::middleware::AuthUser;
@@ -10,25 +10,56 @@ use crate::error::AppError;
 use crate::models::comment::{Comment, CommentDto};
 use crate::models::hashtag::{self, Hashtag};
 use crate::models::upload::Upload;
+use crate::services::config;
 use crate::state::AppState;
 
-/// Reject the request when the event's uploads (and, by extension, social
-/// interaction) are locked. Mirrors the guard in the upload handler.
-async fn require_event_open(state: &AppState) -> Result<(), AppError> {
-    let event = crate::models::event::Event::find_by_slug(&state.pool, &state.config.event_slug)
-        .await?
-        .ok_or_else(|| AppError::NotFound("Event nicht gefunden.".into()))?;
-    if event.uploads_locked_at.is_some() {
-        return Err(AppError::Forbidden("Das Event ist geschlossen.".into()));
+/// Throttle a social write. Keyed PER USER, like the feed and upload limits and for the same
+/// reason: at a venue every guest sits behind one NAT, so an IP key hands the whole party a
+/// single bucket and the most active guest starves everyone else.
+///
+/// These were the only mutating endpoints in the app with no limit at all — the coverage was
+/// asymmetric, not deliberately open. The ceiling is set well above anything a real guest
+/// produces; this bounds a script, not an enthusiastic double-tapper.
+async fn check_social_rate(state: &AppState, user_id: Uuid) -> Result<(), AppError> {
+    let rate_limits_on = config::get_bool(&state.config_cache, "rate_limits_enabled", true).await;
+    let social_rate_on = config::get_bool(&state.config_cache, "social_rate_enabled", true).await;
+    if !(rate_limits_on && social_rate_on) {
+        return Ok(());
     }
-    Ok(())
+    let rate_limit = config::get_usize(&state.config_cache, "social_rate_per_min", 120).await;
+    // ONE bucket across likes, comments and comment deletions. Separate buckets would let a
+    // caller triple the aggregate write rate just by alternating between them.
+    state
+        .rate_limiter
+        .check_with_retry(
+            format!("social:{user_id}"),
+            rate_limit,
+            std::time::Duration::from_secs(60),
+        )
+        .map_err(|retry_after_secs| {
+            AppError::TooManyRequests(
+                "Zu viele Aktionen. Bitte warte kurz und versuche es erneut.".into(),
+                Some(retry_after_secs),
+            )
+        })
+}
+
+#[derive(Serialize)]
+pub struct LikeResponse {
+    /// The caller's like state *after* this toggle. The client sets `liked_by_me` from
+    /// this rather than blind-inverting local state — otherwise a second device (same
+    /// recovered user) drifts, since the `like-update` broadcast only carries `like_count`.
+    pub liked: bool,
+    /// Fresh like count, or `null` if the (best-effort) count query hiccuped. The client
+    /// keeps its current count when this is null rather than adopting a wrong number.
+    pub like_count: Option<i64>,
 }
 
 pub async fn toggle_like(
     State(state): State<AppState>,
     auth: AuthUser,
     Path(upload_id): Path<Uuid>,
-) -> Result<StatusCode, AppError> {
+) -> Result<Json<LikeResponse>, AppError> {
     // Check if user is banned
     let user = crate::models::user::User::find_by_id(&state.pool, auth.user_id)
         .await?
@@ -36,6 +67,7 @@ pub async fn toggle_like(
     if user.is_banned {
         return Err(AppError::Forbidden("Du bist gesperrt.".into()));
     }
+    check_social_rate(&state, auth.user_id).await?;
 
     // Event-scope: the upload must belong to the caller's event (404 otherwise),
     // matching the host handlers' find_by_id_and_event pattern.
@@ -43,10 +75,11 @@ pub async fn toggle_like(
         .await?
         .ok_or_else(|| AppError::NotFound("Upload nicht gefunden.".into()))?;
 
-    // A closed event freezes social interaction too, matching the upload handler.
-    require_event_open(&state).await?;
+    // NOTE: liking is intentionally allowed while the event is locked. Locking
+    // ("Event schließen") freezes *new uploads* only — likes, comments and
+    // browsing stay open (USER_JOURNEYS §9.3, FEATURES capability matrix).
 
-    // Try to insert; if conflict, delete (toggle)
+    // Try to insert; if conflict, delete (toggle). `liked` = the caller's state afterwards.
     let result = sqlx::query(
         "INSERT INTO \"like\" (upload_id, user_id) VALUES ($1, $2)
          ON CONFLICT (upload_id, user_id) DO NOTHING",
@@ -56,7 +89,8 @@ pub async fn toggle_like(
     .execute(&state.pool)
     .await?;
 
-    if result.rows_affected() == 0 {
+    let liked = result.rows_affected() > 0;
+    if !liked {
         // Already liked — remove
         sqlx::query("DELETE FROM \"like\" WHERE upload_id = $1 AND user_id = $2")
             .bind(upload_id)
@@ -66,24 +100,29 @@ pub async fn toggle_like(
     }
 
     // Fresh count so feed clients can patch the single card in place instead of
-    // refetching page 1 (mirrors v_feed.like_count = COUNT(DISTINCT user_id)). The
-    // count + broadcast are a UI optimisation — the like itself is already committed,
-    // so a failure here must not fail the request. Swallow the error and skip the
-    // broadcast; the next event or a pull-to-refresh reconciles the count.
-    if let Ok(like_count) = sqlx::query_scalar::<_, i64>(
+    // refetching page 1 (mirrors v_feed.like_count = COUNT(DISTINCT user_id)). The like
+    // itself is already committed, so a failed count must not fail the request — but we
+    // also must NOT broadcast/return a bogus 0 (that would push like_count: 0 to every
+    // client until the next event). On error we skip the broadcast and return null.
+    let like_count = sqlx::query_scalar::<_, i64>(
         "SELECT COUNT(DISTINCT user_id) FROM \"like\" WHERE upload_id = $1",
     )
     .bind(upload_id)
     .fetch_one(&state.pool)
     .await
-    {
+    .ok();
+
+    if let Some(count) = like_count {
+        // Broadcast the new count so other clients patch their card. Only `like_count` is
+        // shared — each client's own `liked_by_me` only changes via its own toggle (which
+        // now reads it straight from this response).
         let _ = state.sse_tx.send(crate::state::SseEvent {
             event_type: "like-update".to_string(),
-            data: serde_json::json!({ "upload_id": upload_id, "like_count": like_count }).to_string(),
+            data: serde_json::json!({ "upload_id": upload_id, "like_count": count }).to_string(),
         });
     }
 
-    Ok(StatusCode::NO_CONTENT)
+    Ok(Json(LikeResponse { liked, like_count }))
 }
 
 #[derive(Deserialize, Default)]
@@ -123,20 +162,28 @@ pub async fn add_comment(
     Path(upload_id): Path<Uuid>,
     Json(body): Json<AddCommentRequest>,
 ) -> Result<(StatusCode, Json<CommentDto>), AppError> {
+    // Comments can be disabled instance-wide (env COMMENTS_ENABLED). The frontend hides
+    // the UI, but gate the API too so a stale client or direct call can't slip one in.
+    if !state.config.comments_enabled {
+        return Err(AppError::Forbidden("Kommentare sind deaktiviert.".into()));
+    }
+
     let user = crate::models::user::User::find_by_id(&state.pool, auth.user_id)
         .await?
         .ok_or_else(|| AppError::NotFound("Benutzer nicht gefunden.".into()))?;
     if user.is_banned {
         return Err(AppError::Forbidden("Du bist gesperrt.".into()));
     }
+    check_social_rate(&state, auth.user_id).await?;
 
     // Event-scope: only comment on an upload that belongs to the caller's event.
     Upload::find_by_id_and_event(&state.pool, upload_id, auth.event_id)
         .await?
         .ok_or_else(|| AppError::NotFound("Upload nicht gefunden.".into()))?;
 
-    // A closed event freezes social interaction too, matching the upload handler.
-    require_event_open(&state).await?;
+    // NOTE: commenting is intentionally allowed while the event is locked. Locking
+    // freezes *new uploads* only — likes, comments and browsing stay open
+    // (USER_JOURNEYS §9.3, FEATURES capability matrix).
 
     let text = body.body.trim();
     let text_chars = text.chars().count();
@@ -203,6 +250,7 @@ pub async fn delete_comment(
     if auth.is_banned {
         return Err(AppError::Forbidden("Du bist gesperrt.".into()));
     }
+    check_social_rate(&state, auth.user_id).await?;
     let comment = Comment::find_by_id(&state.pool, comment_id)
         .await?
         .ok_or_else(|| AppError::NotFound("Kommentar nicht gefunden.".into()))?;
@@ -213,10 +261,22 @@ pub async fn delete_comment(
 
     // Event-scope: soft_delete_in_event only matches comments whose upload is in
     // the caller's event, so a cross-event comment_id resolves to a 404 here.
-    let deleted = Comment::soft_delete_in_event(&state.pool, comment_id, auth.event_id).await?;
+    let mut tx = state.pool.begin().await?;
+    let deleted = Comment::soft_delete_in_event(&mut tx, comment_id, auth.event_id).await?;
     if !deleted {
         return Err(AppError::NotFound("Kommentar nicht gefunden.".into()));
     }
+    // Comments live only in the HTML viewer, so the ZIP is carried forward, not rebuilt.
+    let regen = crate::services::export::invalidate_and_arm(
+        &mut tx,
+        &state.config.event_slug,
+        crate::services::export::Affects::ViewerOnly,
+    )
+    .await?;
+    tx.commit().await?;
+    if let Some(r) = regen {
+        crate::handlers::host::start_regen(&state, r);
+    }
     let _ = state.sse_tx.send(crate::state::SseEvent::new(
         "comment-deleted",
         serde_json::json!({ "comment_id": comment_id, "upload_id": comment.upload_id }).to_string(),

backend/src/handlers/sse.rs

@@ -1,13 +1,14 @@
 use std::convert::Infallible;
 use std::time::Duration;
 
+use axum::Json;
 use axum::extract::{Query, State};
 use axum::response::sse::{Event, KeepAlive, Sse};
-use axum::Json;
 use futures::stream::Stream;
 use serde::{Deserialize, Serialize};
-use tokio_stream::wrappers::BroadcastStream;
 use tokio_stream::StreamExt;
+use tokio_stream::wrappers::BroadcastStream;
+use tokio_stream::wrappers::errors::BroadcastStreamRecvError;
 
 use crate::auth::middleware::AuthUser;
 use crate::error::AppError;
@@ -22,6 +23,10 @@ pub struct SseQuery {
 #[derive(Serialize)]
 pub struct StreamTicketResponse {
     pub ticket: String,
+    /// Server clock at mint time — the client seeds its SSE reconnect cursor from this
+    /// instead of `new Date()`, so a skewed browser clock can't drop uploads. See
+    /// `DeltaResponse::server_time`.
+    pub server_time: chrono::DateTime<chrono::Utc>,
 }
 
 /// Mint a short-lived single-use SSE ticket. The browser's `EventSource` cannot
@@ -32,9 +37,34 @@ pub struct StreamTicketResponse {
 pub async fn issue_ticket(
     State(state): State<AppState>,
     auth: AuthUser,
-) -> Json<StreamTicketResponse> {
-    let ticket = state.sse_tickets.issue(auth.token_hash);
-    Json(StreamTicketResponse { ticket })
+) -> Result<Json<StreamTicketResponse>, AppError> {
+    // The endpoint had no rate limit at all. Authentication is not a bound here: one valid
+    // session could loop it freely. 60/min is far above a real client (one ticket per SSE
+    // (re)connect, and reconnects are backed off) while capping a loop.
+    if let Err(retry_after_secs) = state.rate_limiter.check_with_retry(
+        format!("sse_ticket:{}", auth.user_id),
+        60,
+        Duration::from_secs(60),
+    ) {
+        return Err(AppError::TooManyRequests(
+            "Zu viele Verbindungsversuche. Bitte warte kurz.".into(),
+            Some(retry_after_secs),
+        ));
+    }
+
+    let ticket = state.sse_tickets.issue(auth.token_hash).ok_or_else(|| {
+        AppError::ServiceUnavailable(
+            "Server ist gerade ausgelastet. Live-Updates folgen in Kürze.".into(),
+            Some(30),
+        )
+    })?;
+    let server_time = sqlx::query_scalar("SELECT NOW()")
+        .fetch_one(&state.pool)
+        .await?;
+    Ok(Json(StreamTicketResponse {
+        ticket,
+        server_time,
+    }))
 }
 
 /// SSE stream endpoint. Authenticates via a single-use ticket (see
@@ -58,13 +88,47 @@ pub async fn stream(
         .ok_or_else(|| AppError::Unauthorized("Sitzung nicht gefunden.".into()))?;
 
     let rx = state.sse_tx.subscribe();
-    let stream = BroadcastStream::new(rx).filter_map(|msg| match msg {
+    let events = BroadcastStream::new(rx).filter_map(|msg| match msg {
         Ok(sse_event) => Some(Ok(Event::default()
             .event(sse_event.event_type)
             .data(sse_event.data))),
-        Err(_) => None,
+        // A consumer that falls behind the broadcast buffer would otherwise silently
+        // lose events, leaving its feed permanently stale. Instead of dropping the
+        // gap, tell the client to resync — the frontend responds by running a full
+        // feed-delta fetch (which reconciles both new uploads and deletions).
+        Err(BroadcastStreamRecvError::Lagged(n)) => {
+            tracing::warn!("SSE consumer lagged, dropped {n} event(s); emitting resync");
+            Some(Ok(Event::default().event("resync").data(n.to_string())))
+        }
     });
 
+    // The session is only checked once at open. Re-validate it periodically so a
+    // logged-out, expired, OR banned session's stream is closed rather than kept alive
+    // until the client happens to disconnect. Bounds a stale stream to ~60s. NOTE: a ban is
+    // deliberately read-only and does NOT revoke sessions (see `ban_user`), so the
+    // `is_banned` re-read below is LOAD-BEARING — it is the only thing that stops a banned
+    // user's live push stream. Do not remove it. Only a *definitive* gone/expired/banned
+    // state ends the stream; a transient DB error just retries next tick.
+    let pool = state.pool.clone();
+    let session_hash = token_hash.clone();
+    let session_gone = async move {
+        let mut ticker = tokio::time::interval(Duration::from_secs(60));
+        ticker.tick().await; // consume the immediate first tick
+        loop {
+            ticker.tick().await;
+            match Session::find_user_by_token_hash(&pool, &session_hash).await {
+                Ok(Some(user)) if !user.is_banned => {} // still valid — keep streaming
+                Ok(Some(_)) => break,                   // banned — cut the stream
+                Ok(None) => break,                      // logged out or expired — stop
+                Err(e) => {
+                    tracing::warn!(error = ?e, "SSE session revalidation query failed; retrying");
+                }
+            }
+        }
+    };
+
+    let stream = futures::StreamExt::take_until(events, Box::pin(session_gone));
+
     Ok(Sse::new(stream).keep_alive(
         KeepAlive::new()
             .interval(Duration::from_secs(30))

backend/src/handlers/test_admin.rs

@@ -13,9 +13,10 @@ use crate::auth::middleware::RequireAdmin;
 use crate::error::AppError;
 use crate::state::AppState;
 
-/// Truncates every event-scoped table, wipes media on disk, and reseeds the
-/// `config` table from migration defaults. Requires an admin JWT — even with
-/// `EVENTSNAP_TEST_MODE=1` it cannot be hit anonymously.
+/// Truncates every event-scoped table, wipes media on disk, and reseeds the `config`
+/// table: numeric values from the migration defaults, but every feature toggle forced
+/// OFF (production seeds them ON — see the note at the reseed below). Requires an admin
+/// JWT — even with `EVENTSNAP_TEST_MODE=1` it cannot be hit anonymously.
 pub async fn truncate_all(
     State(state): State<AppState>,
     RequireAdmin(_auth): RequireAdmin,
@@ -40,15 +41,29 @@ pub async fn truncate_all(
     .execute(&state.pool)
     .await?;
 
-    // Reseed config — mirrors migrations 005 and 009. Kept in sync by hand
-    // because pulling SQL out of the migration files at runtime is fragile.
+    // Reseed config. The NUMERIC values mirror migrations 005/015/016/017/019; the BOOLEAN
+    // toggles deliberately do NOT — migration 009 seeds every one of them `true`
+    // (production), and this forces them `false` so the suite isn't fighting rate limits
+    // and quotas it isn't testing.
+    //
+    // Be aware of what that costs: this runs as an auto-fixture before EVERY test, so no
+    // test starts from production's config unless it explicitly turns a toggle back on
+    // (02-upload/rate-limit, 07-adversarial/ddos, 01-auth/rate-limit-nat, …). That blind
+    // spot is exactly why an entire class of per-IP limiter bugs went unnoticed: the
+    // limiters were simply off. When adding a limiter or quota, add a spec that enables it.
+    //
+    // Kept in sync by hand because pulling SQL out of the migration files at runtime is
+    // fragile — if you add a config key in a migration, add it here too.
     sqlx::query(
         r#"INSERT INTO config (key, value) VALUES
             ('max_image_size_mb',          '20'),
             ('max_video_size_mb',          '500'),
-            ('upload_rate_per_hour',       '10'),
+            ('upload_rate_per_hour',       '100'),
             ('feed_rate_per_min',          '60'),
             ('export_rate_per_day',        '3'),
+            ('join_ip_rate_per_min',       '60'),
+            ('recover_ip_rate_per_min',    '30'),
+            ('social_rate_per_min',        '120'),
             ('quota_tolerance',            '0.75'),
             ('estimated_guest_count',      '100'),
             ('compression_concurrency',    '2'),
@@ -57,6 +72,8 @@ pub async fn truncate_all(
             ('feed_rate_enabled',          'false'),
             ('export_rate_enabled',        'false'),
             ('join_rate_enabled',          'false'),
+            ('social_rate_enabled',        'false'),
+            ('admin_login_rate_enabled',   'false'),
             ('quota_enabled',              'false'),
             ('storage_quota_enabled',      'false'),
             ('upload_count_quota_enabled', 'false'),
@@ -80,6 +97,31 @@ pub async fn truncate_all(
     // counters don't leak into the next one.
     state.rate_limiter.clear();
 
+    // The reseed above wrote the `config` table directly (bypassing patch_config), so
+    // the cache must be invalidated too — otherwise the first request after a truncate
+    // could serve the previous test's toggles.
+    state.config_cache.invalidate();
+
+    // The other two in-memory singletons that TRUNCATE used to leave standing.
+    //
+    // `disk_cache` holds a free-space reading for up to its TTL. TRUNCATE has just deleted every
+    // uploaded file, which materially changes free space — so without this the next test can
+    // compute a storage quota from the PREVIOUS test's disk. That was harmless only while quotas
+    // were globally disabled in e2e (they no longer are: see specs/02-upload/quota.spec.ts, which
+    // steers the per-user limit off `free_disk_bytes`), i.e. two holes were masking each other.
+    state.disk_cache.invalidate();
+
+    // `sse_tickets` maps a ticket to a session token hash. TRUNCATE deletes the sessions, so every
+    // surviving ticket is a dangling reference to a user that no longer exists.
+    state.sse_tickets.clear();
+
+    // Invalidate any in-flight/queued compression task spawned by the previous test. Without this a
+    // task still waiting on the concurrency semaphore wakes AFTER this wipe, fails to find its
+    // (now-deleted) file, and broadcasts upload-error/upload-deleted into the NEXT test's SSE
+    // stream. (Export workers are already inert across a truncate: they are epoch-guarded on the
+    // event row, and truncate gives the event a fresh random UUID, so their writes match nothing.)
+    state.compression.bump_generation();
+
     Ok(StatusCode::NO_CONTENT)
 }
 

backend/src/main.rs

@@ -1,8 +1,7 @@
 use anyhow::Result;
+use axum::Router;
 use axum::extract::DefaultBodyLimit;
 use axum::routing::{delete, get, patch, post};
-use axum::Router;
-use tower_http::services::ServeDir;
 use tower_http::trace::TraceLayer;
 use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};
 
@@ -27,9 +26,17 @@ async fn main() -> Result<()> {
     dotenvy::dotenv().ok();
 
     tracing_subscriber::registry()
-        .with(tracing_subscriber::EnvFilter::try_from_default_env().unwrap_or_else(|_| {
-            "eventsnap_backend=debug,tower_http=debug".into()
-        }))
+        .with(
+            // `info`, not `debug`. A stock deploy sets RUST_LOG nowhere (it is absent from
+            // .env.example and was absent from docker-compose.yml), so this fallback IS the
+            // production level — and at `debug` the TraceLayer below emits a line per request
+            // AND per response, into a log file that had no rotation. `tower_http=warn`
+            // rather than `info` states the intent: those spans are diagnostics, not an
+            // access log, and a future `DefaultOnResponse::new().level(Level::INFO)` should
+            // not silently re-enable them.
+            tracing_subscriber::EnvFilter::try_from_default_env()
+                .unwrap_or_else(|_| "eventsnap_backend=info,tower_http=warn".into()),
+        )
         .with(tracing_subscriber::fmt::layer())
         .init();
 
@@ -44,12 +51,39 @@ async fn main() -> Result<()> {
 
     let state = AppState::new(pool.clone(), config.clone());
 
+    // Regenerate image derivatives an older pipeline produced: the big-screen display for
+    // uploads processed before it existed (v0.17.x), and anything predating the current
+    // DERIVATIVES_REV (rev 1 applies the EXIF orientation, without which every portrait
+    // phone photo is stored sideways). Fire-and-forget behind the compression semaphore;
+    // originals are never touched, so a failure just retries on the next start.
+    state.compression.backfill_stale_derivatives().await;
+
+    // Re-extract poster frames for videos a restart interrupted. `startup_recovery` above
+    // marks their compression `failed` but nothing re-enqueued them, so `thumbnail_path`
+    // stayed NULL for the rest of the event. Shares the attempt budget with the image
+    // backfill, so a clip that genuinely yields no frame stops being retried.
+    state.compression.backfill_video_posters().await;
+
+    // Re-spawn exports for events that were released but whose keepsake never finished
+    // (crash mid-export). Needs the media/export paths + SSE sender, so it runs here
+    // rather than inside `startup_recovery`. Fire-and-forget: the workers run in the
+    // background; the HTTP server can start accepting requests meanwhile.
+    services::export::recover_exports(
+        pool.clone(),
+        config.media_path.clone(),
+        config.export_path.clone(),
+        config.comments_enabled,
+        state.sse_tx.clone(),
+    )
+    .await;
+
     // Hourly background hygiene: prune expired sessions, evict cold rate-limiter
     // keys. Keeps the DB and process from growing unboundedly over multi-day events.
     services::maintenance::spawn_periodic_tasks(
         pool,
         state.rate_limiter.clone(),
         state.sse_tickets.clone(),
+        config.media_path.clone(),
     );
 
     // Ensure media directories exist
@@ -57,17 +91,27 @@ async fn main() -> Result<()> {
 
     let api = Router::new()
         // Auth
+        .route("/api/v1/event", get(handlers::public::get_public_event))
         .route("/api/v1/join", post(auth::handlers::join))
         .route("/api/v1/recover", post(auth::handlers::recover))
+        // Forgotten-PIN escape hatch: ask a host to reset it (unauthenticated, throttled).
+        .route(
+            "/api/v1/recover/request",
+            post(auth::handlers::request_pin_reset),
+        )
         .route("/api/v1/admin/login", post(auth::handlers::admin_login))
         .route("/api/v1/session", delete(auth::handlers::logout))
+        // "Sign out everywhere" — revoke all of the caller's sessions.
+        .route("/api/v1/sessions", delete(auth::handlers::logout_all))
         // Upload — HTTP-level body cap as an OOM backstop. The handler still enforces
         // the precise per-class limits from DB config (max_image/video_size_mb); this
         // layer just stops a multi-GB body from being buffered into memory before that
         // check runs. Sized generously above the default 500 MB video limit + multipart
         // overhead — if an admin raises max_video_size_mb above this, bump MAX_UPLOAD_BYTES.
-        .route("/api/v1/upload", post(handlers::upload::upload)
-            .route_layer(DefaultBodyLimit::max(MAX_UPLOAD_BYTES)))
+        .route(
+            "/api/v1/upload",
+            post(handlers::upload::upload).route_layer(DefaultBodyLimit::max(MAX_UPLOAD_BYTES)),
+        )
         .route(
             "/api/v1/upload/{id}",
             patch(handlers::upload::edit_upload).delete(handlers::upload::delete_upload),
@@ -76,6 +120,21 @@ async fn main() -> Result<()> {
             "/api/v1/upload/{id}/original",
             get(handlers::upload::get_original),
         )
+        // Preview/thumbnail variants are gated the same way as originals (visibility
+        // check + direct /media block below) so moderation actually revokes access to
+        // the displayed images, not just the full-res download.
+        .route(
+            "/api/v1/upload/{id}/preview",
+            get(handlers::upload::get_preview),
+        )
+        .route(
+            "/api/v1/upload/{id}/display",
+            get(handlers::upload::get_display),
+        )
+        .route(
+            "/api/v1/upload/{id}/thumbnail",
+            get(handlers::upload::get_thumbnail),
+        )
         // Current-user endpoints (live quota estimate, profile + privacy note bundle)
         .route("/api/v1/me/context", get(handlers::me::get_context))
         .route("/api/v1/me/quota", get(handlers::me::get_quota))
@@ -84,33 +143,77 @@ async fn main() -> Result<()> {
         .route("/api/v1/feed/delta", get(handlers::feed::feed_delta))
         .route("/api/v1/hashtags", get(handlers::feed::hashtags))
         // Social
-        .route("/api/v1/upload/{id}/like", post(handlers::social::toggle_like))
+        .route(
+            "/api/v1/upload/{id}/like",
+            post(handlers::social::toggle_like),
+        )
         .route(
             "/api/v1/upload/{id}/comments",
             get(handlers::social::list_comments).post(handlers::social::add_comment),
         )
-        .route("/api/v1/comment/{id}", delete(handlers::social::delete_comment))
+        .route(
+            "/api/v1/comment/{id}",
+            delete(handlers::social::delete_comment),
+        )
         // SSE
         .route("/api/v1/stream", get(handlers::sse::stream))
         .route("/api/v1/stream/ticket", post(handlers::sse::issue_ticket))
         // Host Dashboard
         .route("/api/v1/host/event", get(handlers::host::get_event_status))
-        .route("/api/v1/host/event/close", post(handlers::host::close_event))
+        .route(
+            "/api/v1/host/event/close",
+            post(handlers::host::close_event),
+        )
         .route("/api/v1/host/event/open", post(handlers::host::open_event))
-        .route("/api/v1/host/gallery/release", post(handlers::host::release_gallery))
+        .route(
+            "/api/v1/host/gallery/release",
+            post(handlers::host::release_gallery),
+        )
+        // Escape hatch: force a keepsake rebuild. Without it a failed export is terminal at runtime
+        // (release_gallery refuses an already-released event; recovery only runs at boot).
+        .route(
+            "/api/v1/host/export/rebuild",
+            post(handlers::host::rebuild_export),
+        )
         .route("/api/v1/host/users", get(handlers::host::list_users))
-        .route("/api/v1/host/users/{id}/ban", post(handlers::host::ban_user))
-        .route("/api/v1/host/users/{id}/unban", post(handlers::host::unban_user))
-        .route("/api/v1/host/users/{id}/role", patch(handlers::host::set_role))
+        .route(
+            "/api/v1/host/users/{id}/ban",
+            post(handlers::host::ban_user),
+        )
+        .route(
+            "/api/v1/host/users/{id}/unban",
+            post(handlers::host::unban_user),
+        )
+        .route(
+            "/api/v1/host/users/{id}/role",
+            patch(handlers::host::set_role),
+        )
         .route(
             "/api/v1/host/users/{id}/pin-reset",
             post(handlers::host::reset_user_pin),
         )
-        .route("/api/v1/host/upload/{id}", delete(handlers::host::host_delete_upload))
-        .route("/api/v1/host/comment/{id}", delete(handlers::host::host_delete_comment))
+        .route(
+            "/api/v1/host/pin-reset-requests",
+            get(handlers::host::list_pin_reset_requests),
+        )
+        .route(
+            "/api/v1/host/pin-reset-requests/{id}",
+            delete(handlers::host::dismiss_pin_reset_request),
+        )
+        .route(
+            "/api/v1/host/upload/{id}",
+            delete(handlers::host::host_delete_upload),
+        )
+        .route(
+            "/api/v1/host/comment/{id}",
+            delete(handlers::host::host_delete_comment),
+        )
         // Export (all authenticated users)
         .route("/api/v1/export/status", get(handlers::admin::export_status))
-        .route("/api/v1/export/ticket", post(handlers::admin::export_ticket))
+        .route(
+            "/api/v1/export/ticket",
+            post(handlers::admin::export_ticket),
+        )
         .route("/api/v1/export/zip", get(handlers::admin::download_zip))
         .route("/api/v1/export/html", get(handlers::admin::download_html))
         // Admin Dashboard
@@ -119,7 +222,10 @@ async fn main() -> Result<()> {
             "/api/v1/admin/config",
             get(handlers::admin::get_config).patch(handlers::admin::patch_config),
         )
-        .route("/api/v1/admin/export/jobs", get(handlers::admin::get_export_jobs));
+        .route(
+            "/api/v1/admin/export/jobs",
+            get(handlers::admin::get_export_jobs),
+        );
 
     // Test-only route: a hard reset for the Playwright E2E harness. The handler
     // is compiled in always, but the route is only attached when
@@ -138,19 +244,103 @@ async fn main() -> Result<()> {
         api
     };
 
-    // Serve media files from disk
-    let media_service = ServeDir::new(&config.media_path);
-
+    // NOTE: media is deliberately NOT served over HTTP.
+    //
+    // Files live under `media_path` so the compression worker and the export job can read
+    // them off disk, but nothing may pull them straight from `/media/**` — that bypasses
+    // the visibility checks (soft-delete + ban-hide) that make a host takedown stick.
+    // Every legitimate fetch goes through `/api/v1/upload/{id}/{original,preview,display,
+    // thumbnail}`, which filter via `find_visible_media`; those are the only media URLs the
+    // backend ever emits (see `handlers::feed`).
+    //
+    // This used to be a `ServeDir` on `/media` with four `nest_service` blockers on the
+    // subtrees above it. That was bypassable: axum routes on the RAW path while `ServeDir`
+    // percent-decodes afterwards, so `/media/%70reviews/{id}.jpg` missed every blocker,
+    // fell through to the `ServeDir`, and was decoded back to `previews/` on disk — serving
+    // a taken-down photo to anyone, unauthenticated. Any single escaped byte worked, in all
+    // four subtrees. Deleting the route removes the vector outright rather than racing the
+    // decoder; `/media/**` now 404s regardless of encoding.
     let router = Router::new()
+        // Liveness. Stays dependency-free — the compose healthcheck gates Caddy's startup
+        // on it, so anything that can fail transiently must NOT be in here.
         .route("/health", get(|| async { "ok" }))
+        // Readiness. Touches the pool; for an external monitor, not for the compose gate.
+        .route("/health/ready", get(handlers::health::ready))
         .merge(api)
-        .nest_service("/media", media_service)
         .layer(TraceLayer::new_for_http())
         .with_state(state);
 
     let listener = tokio::net::TcpListener::bind(("0.0.0.0", config.app_port)).await?;
     tracing::info!("listening on {}", listener.local_addr()?);
-    axum::serve(listener, router).await?;
+    // `into_make_service_with_connect_info` is required by the pre-auth handlers, which
+    // extract `ConnectInfo<SocketAddr>` to use the peer address as the rate-limit key when
+    // X-Forwarded-For is absent. Without it those extractors fail at runtime.
+    axum::serve(
+        listener,
+        router.into_make_service_with_connect_info::<std::net::SocketAddr>(),
+    )
+    .with_graceful_shutdown(shutdown_signal())
+    .await?;
 
     Ok(())
 }
+
+/// Hard cap on how long we wait for in-flight connections to drain after a shutdown
+/// signal. Uploads (streamed to disk) finish in well under this; the cap exists because
+/// long-lived SSE streams never end on their own and would otherwise keep the graceful
+/// drain — and thus the process — pending until the orchestrator force-kills it.
+const SHUTDOWN_GRACE: std::time::Duration = std::time::Duration::from_secs(10);
+
+/// Resolves on SIGINT (Ctrl-C) or SIGTERM (container stop / deploy). Letting
+/// `axum::serve` drain in-flight requests on this signal means a redeploy no longer
+/// truncates uploads mid-flight; any background compression/export half-states that a
+/// hard kill would leave are already reconciled by `startup_recovery` on the next boot.
+///
+/// Once the signal fires we also arm a detached backstop that force-exits after
+/// [`SHUTDOWN_GRACE`]. Without it, open SSE streams (which have no natural end) would
+/// hold the graceful drain open indefinitely; the backstop bounds shutdown regardless
+/// of the orchestrator's own kill timeout. If the drain completes first, `main` returns
+/// and the process exits before the timer ever fires.
+async fn shutdown_signal() {
+    let ctrl_c = async {
+        let _ = tokio::signal::ctrl_c().await;
+    };
+
+    #[cfg(unix)]
+    let terminate = async {
+        match tokio::signal::unix::signal(tokio::signal::unix::SignalKind::terminate()) {
+            Ok(mut sig) => {
+                sig.recv().await;
+            }
+            Err(e) => {
+                tracing::warn!(error = ?e, "failed to install SIGTERM handler");
+                // Never resolve — fall back to ctrl_c only.
+                std::future::pending::<()>().await;
+            }
+        }
+    };
+
+    #[cfg(not(unix))]
+    let terminate = std::future::pending::<()>();
+
+    tokio::select! {
+        _ = ctrl_c => {}
+        _ = terminate => {}
+    }
+
+    tracing::info!(
+        "shutdown signal received, draining in-flight requests (max {}s)",
+        SHUTDOWN_GRACE.as_secs()
+    );
+
+    // Backstop: if the graceful drain is still blocked after the grace window (almost
+    // always because SSE streams are still open), exit anyway so deploys aren't stalled.
+    tokio::spawn(async {
+        tokio::time::sleep(SHUTDOWN_GRACE).await;
+        tracing::warn!(
+            "graceful drain exceeded {}s (likely open SSE streams); forcing exit",
+            SHUTDOWN_GRACE.as_secs()
+        );
+        std::process::exit(0);
+    });
+}

backend/src/models/comment.rs

@@ -3,6 +3,10 @@ use serde::Serialize;
 use sqlx::PgPool;
 use uuid::Uuid;
 
+// Row shape for `comment`: every field is populated by sqlx from `SELECT *` / `RETURNING *`.
+// `deleted_at` is not read in Rust today (the soft-delete filter lives in SQL), but it is part of
+// the row and stays here so the struct keeps mirroring the table.
+#[allow(dead_code)]
 #[derive(Debug, sqlx::FromRow)]
 pub struct Comment {
     pub id: Uuid,
@@ -79,26 +83,18 @@ impl Comment {
     }
 
     pub async fn find_by_id(pool: &PgPool, id: Uuid) -> Result<Option<Self>, sqlx::Error> {
-        sqlx::query_as::<_, Self>(
-            "SELECT * FROM comment WHERE id = $1 AND deleted_at IS NULL",
-        )
-        .bind(id)
-        .fetch_optional(pool)
-        .await
-    }
-
-    pub async fn soft_delete(pool: &PgPool, id: Uuid) -> Result<(), sqlx::Error> {
-        sqlx::query("UPDATE comment SET deleted_at = NOW() WHERE id = $1")
+        sqlx::query_as::<_, Self>("SELECT * FROM comment WHERE id = $1 AND deleted_at IS NULL")
             .bind(id)
-            .execute(pool)
-            .await?;
-        Ok(())
+            .fetch_optional(pool)
+            .await
     }
 
-    /// Event-scoped variant of [`Self::soft_delete`]. Returns `false` if the
-    /// comment doesn't exist or belongs to a different event.
+    /// Event-scoped soft delete. Returns `false` if the comment doesn't exist or belongs to a
+    /// different event.
+    /// Executor-generic so the delete and the keepsake regeneration can share one transaction
+    /// (see `Upload::soft_delete_in_event` for why that must be atomic).
     pub async fn soft_delete_in_event(
-        pool: &PgPool,
+        conn: &mut sqlx::PgConnection,
         id: Uuid,
         event_id: Uuid,
     ) -> Result<bool, sqlx::Error> {
@@ -111,7 +107,7 @@ impl Comment {
         )
         .bind(id)
         .bind(event_id)
-        .execute(pool)
+        .execute(conn)
         .await?;
         Ok(result.rows_affected() > 0)
     }

backend/src/models/event.rs

@@ -2,6 +2,11 @@ use chrono::{DateTime, Utc};
 use sqlx::PgPool;
 use uuid::Uuid;
 
+// Row shape for `event`: every field is populated by sqlx from `SELECT *` / `RETURNING *`. Several
+// (`slug`, `cover_image_path`, `export_epoch`, `created_at`) are not read through this struct today
+// — callers that need them query the column directly — but they are part of the row and stay here so
+// the struct keeps mirroring the table.
+#[allow(dead_code)]
 #[derive(Debug, sqlx::FromRow)]
 pub struct Event {
     pub id: Uuid,
@@ -11,8 +16,11 @@ pub struct Event {
     pub is_active: bool,
     pub uploads_locked_at: Option<DateTime<Utc>>,
     pub export_released_at: Option<DateTime<Utc>>,
-    pub export_zip_ready: bool,
-    pub export_html_ready: bool,
+    /// Monotonic generation counter for the keepsake. Bumped in the SAME UPDATE as any change to
+    /// `export_released_at` (release and reopen are its only writers). An export is downloadable
+    /// iff a `done` `export_job` row carries this exact epoch — readiness is derived from that,
+    /// never stored, so it cannot drift and no worker can resurrect it. See migration 014.
+    pub export_epoch: i64,
     pub created_at: DateTime<Utc>,
 }
 
@@ -25,13 +33,11 @@ impl Event {
     }
 
     pub async fn create(pool: &PgPool, slug: &str, name: &str) -> Result<Self, sqlx::Error> {
-        sqlx::query_as::<_, Self>(
-            "INSERT INTO event (slug, name) VALUES ($1, $2) RETURNING *",
-        )
-        .bind(slug)
-        .bind(name)
-        .fetch_one(pool)
-        .await
+        sqlx::query_as::<_, Self>("INSERT INTO event (slug, name) VALUES ($1, $2) RETURNING *")
+            .bind(slug)
+            .bind(name)
+            .fetch_one(pool)
+            .await
     }
 
     pub async fn find_or_create(

backend/src/models/hashtag.rs

@@ -1,6 +1,8 @@
-use sqlx::PgPool;
 use uuid::Uuid;
 
+// Row shape for `hashtag`, populated by sqlx from `RETURNING *` in `upsert`. Callers only use
+// `id` today; `event_id`/`tag` are the rest of the row and stay part of the struct.
+#[allow(dead_code)]
 #[derive(Debug, sqlx::FromRow)]
 pub struct Hashtag {
     pub id: Uuid,
@@ -61,22 +63,6 @@ impl Hashtag {
             .await?;
         Ok(())
     }
-
-    pub async fn tags_for_upload(
-        pool: &PgPool,
-        upload_id: Uuid,
-    ) -> Result<Vec<String>, sqlx::Error> {
-        let rows: Vec<(String,)> = sqlx::query_as(
-            "SELECT h.tag FROM hashtag h
-             JOIN upload_hashtag uh ON uh.hashtag_id = h.id
-             WHERE uh.upload_id = $1
-             ORDER BY h.tag",
-        )
-        .bind(upload_id)
-        .fetch_all(pool)
-        .await?;
-        Ok(rows.into_iter().map(|r| r.0).collect())
-    }
 }
 
 /// Extract `#hashtags` from text (caption or body). Tags are restricted to
@@ -136,14 +122,20 @@ mod tests {
         assert_eq!(extract_hashtags(&format!("#{ok}")), vec![ok.clone()]);
         // 41+ chars → dropped entirely (not truncated).
         let too_long = "a".repeat(41);
-        assert_eq!(extract_hashtags(&format!("#{too_long}")), Vec::<String>::new());
+        assert_eq!(
+            extract_hashtags(&format!("#{too_long}")),
+            Vec::<String>::new()
+        );
     }
 
     #[test]
     fn duplicate_tags_are_returned_verbatim_not_deduplicated() {
         // Dedup is the DB's job (Hashtag::upsert ON CONFLICT); extraction returns each
         // occurrence so callers can count/link them independently. Case folds to lower.
-        assert_eq!(extract_hashtags("#fun #Fun #fun!"), vec!["fun", "fun", "fun"]);
+        assert_eq!(
+            extract_hashtags("#fun #Fun #fun!"),
+            vec!["fun", "fun", "fun"]
+        );
     }
 
     #[test]

backend/src/models/session.rs

@@ -2,6 +2,9 @@ use chrono::{DateTime, Utc};
 use sqlx::PgPool;
 use uuid::Uuid;
 
+// Row shape for `session`, populated by sqlx from `RETURNING *`. Session validation is done in SQL
+// (expiry/last-seen predicates), so no field is read in Rust — the struct is the row's shape.
+#[allow(dead_code)]
 #[derive(Debug, sqlx::FromRow)]
 pub struct Session {
     pub id: Uuid,
@@ -43,22 +46,65 @@ impl Session {
         .await
     }
 
-    pub async fn touch(pool: &PgPool, id: Uuid) -> Result<(), sqlx::Error> {
-        sqlx::query("UPDATE session SET last_seen_at = NOW() WHERE id = $1")
-            .bind(id)
-            .execute(pool)
-            .await?;
+    /// Resolve a session token straight to its live user row in one round-trip.
+    ///
+    /// The auth extractor runs on every authenticated request and used to do two
+    /// sequential queries (session lookup, then user lookup); this collapses them into
+    /// a single `session JOIN "user"`. The `expires_at` guard mirrors
+    /// [`Self::find_by_token_hash`], and the user row is read live (role/ban are never
+    /// trusted from the JWT). Returns `None` when the session is missing/expired.
+    pub async fn find_user_by_token_hash(
+        pool: &PgPool,
+        token_hash: &str,
+    ) -> Result<Option<crate::models::user::User>, sqlx::Error> {
+        sqlx::query_as::<_, crate::models::user::User>(
+            "SELECT u.*
+             FROM session s
+             JOIN \"user\" u ON u.id = s.user_id
+             WHERE s.token_hash = $1 AND s.expires_at > NOW()",
+        )
+        .bind(token_hash)
+        .fetch_optional(pool)
+        .await
+    }
+
+    /// Touch `last_seen_at` AND slide `expires_at` forward by `expiry_days` from now, so
+    /// an actively-used session never hits the fixed 30-day cliff (it renews on every
+    /// authenticated request). An idle session still expires `expiry_days` after its last
+    /// activity. Keyed by token hash so the auth extractor needs no prior id lookup.
+    pub async fn touch_and_renew(
+        pool: &PgPool,
+        token_hash: &str,
+        expiry_days: i64,
+    ) -> Result<(), sqlx::Error> {
+        sqlx::query(
+            "UPDATE session
+             SET last_seen_at = NOW(),
+                 expires_at = NOW() + ($2 || ' days')::interval
+             WHERE token_hash = $1",
+        )
+        .bind(token_hash)
+        .bind(expiry_days.to_string())
+        .execute(pool)
+        .await?;
         Ok(())
     }
 
-    pub async fn delete_by_token_hash(
-        pool: &PgPool,
-        token_hash: &str,
-    ) -> Result<(), sqlx::Error> {
+    pub async fn delete_by_token_hash(pool: &PgPool, token_hash: &str) -> Result<(), sqlx::Error> {
         sqlx::query("DELETE FROM session WHERE token_hash = $1")
             .bind(token_hash)
             .execute(pool)
             .await?;
         Ok(())
     }
+
+    /// Revoke every session for a user. Backs "sign out everywhere" and the forced
+    /// re-auth after a host PIN-reset or a ban. Returns the number of sessions cleared.
+    pub async fn delete_all_for_user(pool: &PgPool, user_id: Uuid) -> Result<u64, sqlx::Error> {
+        let r = sqlx::query("DELETE FROM session WHERE user_id = $1")
+            .bind(user_id)
+            .execute(pool)
+            .await?;
+        Ok(r.rows_affected())
+    }
 }

backend/src/models/upload.rs

@@ -3,6 +3,10 @@ use serde::Serialize;
 use sqlx::PgPool;
 use uuid::Uuid;
 
+// Row shape for `upload`: every field is populated by sqlx from `RETURNING *` in `create`. Callers
+// mostly use `id` and hand the rest to the compression/feed queries, so most fields are never read
+// through this struct — they stay here so it keeps mirroring the table.
+#[allow(dead_code)]
 #[derive(Debug, sqlx::FromRow)]
 pub struct Upload {
     pub id: Uuid,
@@ -35,6 +39,17 @@ pub struct UploadDto {
     pub created_at: DateTime<Utc>,
 }
 
+/// Minimal projection of an upload's on-disk file paths, used by the visibility-gated
+/// media aliases so they don't hydrate the entire `Upload` row per request.
+#[derive(Debug, sqlx::FromRow)]
+pub struct VisibleMedia {
+    pub original_path: String,
+    pub preview_path: Option<String>,
+    pub thumbnail_path: Option<String>,
+    pub display_path: Option<String>,
+    pub mime_type: String,
+}
+
 impl Upload {
     /// Takes any executor so the caller can run it inside a transaction (atomic
     /// quota + insert) or standalone against the pool.
@@ -65,9 +80,25 @@ impl Upload {
         .await
     }
 
-    pub async fn find_by_id(pool: &PgPool, id: Uuid) -> Result<Option<Self>, sqlx::Error> {
-        sqlx::query_as::<_, Self>(
-            "SELECT * FROM upload WHERE id = $1 AND deleted_at IS NULL",
+    /// Lean lookup for the public media aliases (`get_original`/`get_preview`/
+    /// `get_thumbnail`): returns ONLY the file paths + mime for a visible upload —
+    /// excluding soft-deleted rows, hidden owners (`uploads_hidden`), and banned owners
+    /// (`is_banned`) — the same filter `v_feed` applies. So moderation that removes a post
+    /// from the feed also stops its original/preview/thumbnail from being pulled by UUID.
+    ///
+    /// Selects four columns instead of the whole `Upload` row: this runs once per image
+    /// per cache-miss on the media hot path, so we avoid hydrating fields the response
+    /// never uses.
+    pub async fn find_visible_media(
+        pool: &PgPool,
+        id: Uuid,
+    ) -> Result<Option<VisibleMedia>, sqlx::Error> {
+        sqlx::query_as::<_, VisibleMedia>(
+            "SELECT up.original_path, up.preview_path, up.thumbnail_path, up.display_path, up.mime_type
+             FROM upload up
+             JOIN \"user\" u ON u.id = up.user_id
+             WHERE up.id = $1 AND up.deleted_at IS NULL
+               AND u.uploads_hidden = false AND u.is_banned = false",
         )
         .bind(id)
         .fetch_optional(pool)
@@ -104,6 +135,82 @@ impl Upload {
         Ok(())
     }
 
+    pub async fn set_display_path(
+        pool: &PgPool,
+        id: Uuid,
+        display_path: &str,
+    ) -> Result<(), sqlx::Error> {
+        sqlx::query("UPDATE upload SET display_path = $2 WHERE id = $1")
+            .bind(id)
+            .bind(display_path)
+            .execute(pool)
+            .await?;
+        Ok(())
+    }
+
+    /// Stamp which revision of the derivative pipeline produced this row's preview/display,
+    /// so the startup backfill can find rows generated by an older one exactly once.
+    ///
+    /// Also clears the attempt counter: success is the only thing that resets it, and folding
+    /// the reset in here means both the live path and the backfill get it with no extra call
+    /// site to forget.
+    pub async fn set_derivatives_rev(pool: &PgPool, id: Uuid, rev: i16) -> Result<(), sqlx::Error> {
+        sqlx::query(
+            "UPDATE upload
+                SET derivatives_rev = $2, derivative_attempts = 0, derivative_last_error = NULL
+              WHERE id = $1",
+        )
+        .bind(id)
+        .bind(rev)
+        .execute(pool)
+        .await?;
+        Ok(())
+    }
+
+    /// Record that derivative processing is ABOUT to be attempted, returning the new count.
+    ///
+    /// WRITE-AHEAD ON PURPOSE. The failure this bounds is a cgroup SIGKILL: the process
+    /// vanishes mid-work, so no `Err` is returned, no error handler runs and no `Drop` fires.
+    /// A counter incremented after a failure would increment zero times per crash and the
+    /// boot loop would be unchanged. Counting the ATTEMPT is the only thing that survives the
+    /// process dying. The cost is that a genuinely transient failure also burns an attempt —
+    /// acceptable, because the retry budget is per-boot-loop, not per-request, and success
+    /// resets it to zero.
+    /// `None` when the row no longer exists (hard-deleted, or an e2e TRUNCATE landed while the
+    /// task waited on the semaphore) — the caller should abandon quietly rather than treat a
+    /// missing row as a processing failure.
+    pub async fn begin_derivative_attempt(
+        pool: &PgPool,
+        id: Uuid,
+    ) -> Result<Option<i16>, sqlx::Error> {
+        sqlx::query_scalar(
+            "UPDATE upload
+                SET derivative_attempts = derivative_attempts + 1
+              WHERE id = $1
+          RETURNING derivative_attempts",
+        )
+        .bind(id)
+        .fetch_optional(pool)
+        .await
+    }
+
+    /// Store why the last derivative attempt failed. Diagnostics only — nothing branches on it.
+    pub async fn record_derivative_failure(
+        pool: &PgPool,
+        id: Uuid,
+        error: &str,
+    ) -> Result<(), sqlx::Error> {
+        // Bounded: an anyhow chain can be long, and this is written on a failure path that may
+        // repeat across every row of a bad batch.
+        let truncated: String = error.chars().take(500).collect();
+        sqlx::query("UPDATE upload SET derivative_last_error = $2 WHERE id = $1")
+            .bind(id)
+            .bind(truncated)
+            .execute(pool)
+            .await?;
+        Ok(())
+    }
+
     pub async fn set_thumbnail_path(
         pool: &PgPool,
         id: Uuid,
@@ -153,12 +260,17 @@ impl Upload {
     /// Event-scoped variant of [`Self::soft_delete`]. Returns `false` if no row
     /// matched (already deleted, wrong event, or unknown id) so host handlers
     /// can return a clean 404 instead of silently no-op'ing.
+    /// Executor-generic so a caller can run the delete and the keepsake regeneration in ONE
+    /// transaction. They must be atomic: if the delete commits and the regeneration doesn't (a
+    /// dropped handler future, a failed second tx), the taken-down photo stays in the downloadable
+    /// archive forever, and recovery can't tell — the keepsake still looks complete at the current
+    /// epoch, and the host can no longer even find the upload to retry.
     pub async fn soft_delete_in_event(
-        pool: &PgPool,
+        conn: &mut sqlx::PgConnection,
         id: Uuid,
         event_id: Uuid,
     ) -> Result<bool, sqlx::Error> {
-        let mut tx = pool.begin().await?;
+        let tx = conn;
         let row: Option<(Uuid, i64)> = sqlx::query_as(
             "UPDATE upload
              SET deleted_at = NOW()
@@ -183,7 +295,6 @@ impl Upload {
         } else {
             false
         };
-        tx.commit().await?;
         Ok(deleted)
     }
 

backend/src/models/user.rs

@@ -22,6 +22,10 @@ impl UserRole {
     }
 }
 
+// Row shape for `user`: every field is populated by sqlx from `SELECT *` / `RETURNING *`.
+// `uploads_hidden`, `failed_pin_attempts` and `created_at` are enforced/updated in SQL rather than
+// read in Rust, but they are part of the row and stay here so the struct keeps mirroring the table.
+#[allow(dead_code)]
 #[derive(Debug, sqlx::FromRow)]
 pub struct User {
     pub id: Uuid,
@@ -56,6 +60,54 @@ impl User {
         .await
     }
 
+    /// Create a user with an explicit role, in ONE statement.
+    ///
+    /// `create` + a separate `UPDATE ... SET role` is not equivalent: a crash or a pool error
+    /// between the two leaves a GUEST row holding a reserved name, which is exactly the
+    /// poisoned state that bricked admin login — now self-inflicted, and invisible to a
+    /// role-based lookup, so the next login would create yet another.
+    pub async fn create_with_role(
+        pool: &PgPool,
+        event_id: Uuid,
+        display_name: &str,
+        pin_hash: &str,
+        role: UserRole,
+    ) -> Result<Self, sqlx::Error> {
+        sqlx::query_as::<_, Self>(
+            "INSERT INTO \"user\" (event_id, display_name, recovery_pin_hash, role)
+             VALUES ($1, $2, $3, $4)
+             RETURNING *",
+        )
+        .bind(event_id)
+        .bind(display_name)
+        .bind(pin_hash)
+        .bind(role)
+        .fetch_one(pool)
+        .await
+    }
+
+    /// The event's admin, looked up BY ROLE.
+    ///
+    /// The name is not the identity and never was. Looking the admin up by `display_name`
+    /// meant any guest who joined as "Admin" first made the lookup miss, and the fallback
+    /// `create` then violated the case-insensitive unique index from migration 007 — a
+    /// permanent 500 on admin login, recoverable only by hand-editing the database.
+    ///
+    /// `ORDER BY created_at` so a database that somehow acquired two admin rows resolves to a
+    /// stable one rather than alternating between them.
+    pub async fn find_admin_for_event(
+        pool: &PgPool,
+        event_id: Uuid,
+    ) -> Result<Option<Self>, sqlx::Error> {
+        sqlx::query_as::<_, Self>(
+            "SELECT * FROM \"user\" WHERE event_id = $1 AND role = 'admin'
+             ORDER BY created_at ASC LIMIT 1",
+        )
+        .bind(event_id)
+        .fetch_optional(pool)
+        .await
+    }
+
     pub async fn find_by_id(pool: &PgPool, id: Uuid) -> Result<Option<Self>, sqlx::Error> {
         sqlx::query_as::<_, Self>("SELECT * FROM \"user\" WHERE id = $1")
             .bind(id)
@@ -92,33 +144,54 @@ impl User {
         Ok(row.0)
     }
 
+    /// Window after which a failed-PIN streak is forgotten. Matches the lockout duration, so
+    /// "wait out the cooldown" and "start clean" are the same interval to a guest.
+    const PIN_ATTEMPT_DECAY_MINUTES: i64 = 15;
+
+    /// Record a wrong PIN and return the CURRENT streak length.
+    ///
+    /// The counter decays: before this, it only ever cleared on a successful recovery or after
+    /// a lockout expired, so ordinary typos accumulated across days and a guest could arrive at
+    /// an event already most of the way to being locked out by mistakes made the night before.
+    /// Decay is what makes the raised lock threshold safe rather than merely lenient.
     pub async fn increment_failed_pin(pool: &PgPool, id: Uuid) -> Result<i16, sqlx::Error> {
         let row: (i16,) = sqlx::query_as(
             "UPDATE \"user\"
-             SET failed_pin_attempts = failed_pin_attempts + 1
+             SET failed_pin_attempts = CASE
+                     WHEN last_failed_pin_at IS NULL
+                       OR last_failed_pin_at < NOW() - ($2 || ' minutes')::interval
+                     THEN 1
+                     ELSE failed_pin_attempts + 1
+                 END,
+                 last_failed_pin_at = NOW()
              WHERE id = $1
              RETURNING failed_pin_attempts",
         )
         .bind(id)
+        .bind(Self::PIN_ATTEMPT_DECAY_MINUTES.to_string())
         .fetch_one(pool)
         .await?;
         Ok(row.0)
     }
 
-    pub async fn lock_pin(pool: &PgPool, id: Uuid, until: DateTime<Utc>) -> Result<(), sqlx::Error> {
-        sqlx::query(
-            "UPDATE \"user\" SET pin_locked_until = $2 WHERE id = $1",
-        )
-        .bind(id)
-        .bind(until)
-        .execute(pool)
-        .await?;
+    pub async fn lock_pin(
+        pool: &PgPool,
+        id: Uuid,
+        until: DateTime<Utc>,
+    ) -> Result<(), sqlx::Error> {
+        sqlx::query("UPDATE \"user\" SET pin_locked_until = $2 WHERE id = $1")
+            .bind(id)
+            .bind(until)
+            .execute(pool)
+            .await?;
         Ok(())
     }
 
     pub async fn reset_pin_attempts(pool: &PgPool, id: Uuid) -> Result<(), sqlx::Error> {
         sqlx::query(
-            "UPDATE \"user\" SET failed_pin_attempts = 0, pin_locked_until = NULL WHERE id = $1",
+            "UPDATE \"user\"
+                SET failed_pin_attempts = 0, pin_locked_until = NULL, last_failed_pin_at = NULL
+              WHERE id = $1",
         )
         .bind(id)
         .execute(pool)

backend/src/services/compression.rs

@@ -1,9 +1,10 @@
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
+use std::sync::atomic::{AtomicU64, Ordering};
 
 use anyhow::{Context, Result};
 use sqlx::PgPool;
-use tokio::sync::{broadcast, Semaphore};
+use tokio::sync::{Semaphore, broadcast};
 use uuid::Uuid;
 
 use crate::models::upload::Upload;
@@ -12,27 +13,118 @@ use crate::state::SseEvent;
 #[derive(Clone)]
 pub struct CompressionWorker {
     semaphore: Arc<Semaphore>,
+    /// Serialises the memory-heavy image jobs — see `HEAVY_IMAGE_BYTES`. Separate from
+    /// `semaphore` so ordinary photos keep full concurrency.
+    heavy: Arc<Semaphore>,
     pool: PgPool,
     media_path: PathBuf,
     sse_tx: broadcast::Sender<SseEvent>,
+    /// Bumped whenever the underlying data is reset out from under in-flight work (only the e2e
+    /// TRUNCATE does this today). A task captures the value at spawn and abandons itself if it has
+    /// changed by the time it runs — see `process`.
+    generation: Arc<AtomicU64>,
 }
 
 impl CompressionWorker {
-    pub fn new(pool: PgPool, media_path: PathBuf, concurrency: usize, sse_tx: broadcast::Sender<SseEvent>) -> Self {
+    pub fn new(
+        pool: PgPool,
+        media_path: PathBuf,
+        concurrency: usize,
+        sse_tx: broadcast::Sender<SseEvent>,
+    ) -> Self {
         Self {
             semaphore: Arc::new(Semaphore::new(concurrency)),
+            heavy: Arc::new(Semaphore::new(1)),
             pool,
             media_path,
             sse_tx,
+            generation: Arc::new(AtomicU64::new(0)),
         }
     }
 
+    /// Invalidate all in-flight and queued compression work. Called by the e2e TRUNCATE endpoint:
+    /// truncating deletes the upload rows and wipes `media/`, so a worker that was queued on the
+    /// semaphore when the wipe happened would otherwise wake in the NEXT test, fail to find its
+    /// file, and broadcast `upload-error` / `upload-deleted` into that test's live SSE stream —
+    /// corrupting any test that asserts on toasts or feed contents. Bumping the generation makes
+    /// those stale tasks return silently instead. A no-op in production (never called there).
+    pub fn bump_generation(&self) {
+        self.generation.fetch_add(1, Ordering::SeqCst);
+    }
+
+    /// How many times `do_process` is attempted before an upload is given up on. The
+    /// give-up path is user-visible (the photo disappears), so transient infrastructure
+    /// errors must not reach it.
+    const MAX_PROCESS_ATTEMPTS: u32 = 3;
+
+    /// Revision of the image-derivative pipeline. Bump this whenever a change makes existing
+    /// previews/displays wrong, so `backfill_stale_derivatives` regenerates them once on the
+    /// next start. Rev 1 = EXIF orientation is applied.
+    const DERIVATIVES_REV: i16 = 1;
+
+    /// How many times derivative generation may be ATTEMPTED for one upload before it is left
+    /// alone. Counted write-ahead and reset on success — see `Upload::begin_derivative_attempt`.
+    ///
+    /// This is what turns a fatal input from an outage into a blemish. The startup backfill
+    /// runs unconditionally on every boot, so before this bound a row whose processing killed
+    /// the process was re-selected and re-run forever, and `restart: unless-stopped` made that
+    /// an infinite loop that also dropped every SSE stream and truncated every in-flight
+    /// upload on each cycle. Three attempts absorbs genuinely transient infrastructure
+    /// failures (an ENOSPC spike, a pool blip) without ever becoming unbounded.
+    const MAX_DERIVATIVE_ATTEMPTS: i16 = 3;
+
+    /// Rows regenerated per boot. Bounds both the query and the amount of work a single start
+    /// can queue; whatever is left is picked up on the next boot.
+    const BACKFILL_BATCH: i64 = 200;
+
     /// Spawn a background task to process an uploaded file.
     pub fn process(&self, upload_id: Uuid, original_path: String, mime_type: String) {
         let worker = self.clone();
+        let born_at = worker.generation.load(Ordering::SeqCst);
         tokio::spawn(async move {
             let _permit = worker.semaphore.acquire().await;
-            match worker.do_process(upload_id, &original_path, &mime_type).await {
+            // The data this task was queued against may have been reset while it waited for a permit
+            // (e2e TRUNCATE). If so, its file and row are gone; doing anything — including
+            // broadcasting a failure — would leak into an unrelated test. Abandon quietly.
+            if worker.generation.load(Ordering::SeqCst) != born_at {
+                return;
+            }
+            // Retry before giving up. Most failures here are transient and self-clearing —
+            // an ENOSPC spike while several guests upload at once, a momentary DB-pool
+            // exhaustion, a panic inside the image codec — and the give-up path is
+            // user-visible data loss, so it is worth a few seconds to avoid entering it.
+            //
+            // But only for failures that CAN clear. An image that exceeds the decode budget,
+            // is corrupt, or is in an unsupported format fails identically on every attempt,
+            // so retrying it just burns 2s + 4s of backoff and writes three near-identical
+            // warnings before reaching the same conclusion. Give up on those immediately.
+            let mut attempt = 1u32;
+            let outcome = loop {
+                match worker
+                    .do_process(upload_id, &original_path, &mime_type)
+                    .await
+                {
+                    Ok(v) => break Ok(v),
+                    Err(e)
+                        if attempt < Self::MAX_PROCESS_ATTEMPTS
+                            && !crate::services::imaging::is_permanent_image_error(&e) =>
+                    {
+                        tracing::warn!(
+                            error = ?e, %upload_id, attempt,
+                            "compression attempt failed; retrying"
+                        );
+                        tokio::time::sleep(std::time::Duration::from_secs(2u64.pow(attempt))).await;
+                        attempt += 1;
+                        // The data may have been reset while we slept (e2e TRUNCATE).
+                        if worker.generation.load(Ordering::SeqCst) != born_at {
+                            return;
+                        }
+                    }
+                    Err(e) => break Err(e),
+                }
+            };
+
+            match outcome {
                 Ok(_) => {
                     tracing::info!("compression completed for upload {upload_id}");
                     let _ = worker.sse_tx.send(SseEvent {
@@ -41,24 +133,35 @@ impl CompressionWorker {
                     });
                 }
                 Err(e) => {
-                    tracing::error!("compression failed for upload {upload_id}: {e:#}");
-                    // Auto-cleanup: a failed transcode would otherwise leave a
-                    // permanently broken feed card, silently charge the uploader's
-                    // quota, and orphan the original on disk. Refund + soft-delete
-                    // (one tx, so v_feed excludes it), remove the orphan file, then
-                    // tell the uploader (upload-error toast) and evict the card
-                    // everywhere (upload-deleted, already handled by the feed).
+                    tracing::error!(
+                        "compression failed for upload {upload_id} after {attempt} attempt(s): {e:#}"
+                    );
+                    // Refund + soft-delete (one tx, so v_feed excludes it) so a failed
+                    // transcode doesn't leave a permanently broken feed card or silently
+                    // charge the uploader's quota. Then tell the uploader (upload-error
+                    // toast) and evict the card everywhere (upload-deleted).
+                    //
+                    // The ORIGINAL IS DELIBERATELY KEPT. This path used to `remove_file` it
+                    // unconditionally, which meant any transient error — a disk-full blip
+                    // while saving a derivative, a pool hiccup, a panic in the image codec —
+                    // irreversibly destroyed the guest's only copy of a photo they can never
+                    // retake. The row is only soft-deleted, so keeping the bytes makes the
+                    // upload fully recoverable; the file is orphaned rather than lost, and
+                    // the path is logged so it can be found. `backfill_stale_derivatives`
+                    // already refuses to destroy data on error for exactly this reason.
                     let _ = Upload::set_compression_status(&worker.pool, upload_id, "failed").await;
                     if let Err(del) = Upload::soft_delete(&worker.pool, upload_id).await {
                         tracing::warn!(error = ?del, %upload_id, "failed to soft-delete after compression failure");
                     }
-                    let orphan = worker.media_path.join(&original_path);
-                    if let Err(rm) = tokio::fs::remove_file(&orphan).await {
-                        tracing::warn!(error = ?rm, path = %orphan.display(), "failed to remove orphaned original");
-                    }
+                    tracing::warn!(
+                        %upload_id,
+                        path = %worker.media_path.join(&original_path).display(),
+                        "original retained for recovery after compression failure"
+                    );
                     let _ = worker.sse_tx.send(SseEvent {
                         event_type: "upload-error".to_string(),
-                        data: serde_json::json!({ "upload_id": upload_id, "error": e.to_string() }).to_string(),
+                        data: serde_json::json!({ "upload_id": upload_id, "error": e.to_string() })
+                            .to_string(),
                     });
                     let _ = worker.sse_tx.send(SseEvent {
                         event_type: "upload-deleted".to_string(),
@@ -80,137 +183,623 @@ impl CompressionWorker {
         let original = self.media_path.join(original_path);
 
         if mime_type.starts_with("image/") {
-            let preview_rel = self.generate_image_preview(upload_id, &original, mime_type).await?;
+            // Count the attempt BEFORE doing the work — see `begin_derivative_attempt`. If this
+            // input is the one that kills the container, this write is the only record that
+            // survives, and it is what stops the boot backfill replaying it forever.
+            match Upload::begin_derivative_attempt(&self.pool, upload_id).await? {
+                Some(attempts) if attempts > Self::MAX_DERIVATIVE_ATTEMPTS => {
+                    anyhow::bail!(
+                        "derivative generation gave up after {} attempt(s)",
+                        attempts - 1
+                    );
+                }
+                Some(_) => {}
+                // The row vanished while this task waited on the semaphore. Nothing to do, and
+                // reporting a failure would broadcast into a stream that no longer has a card.
+                None => return Ok(()),
+            }
+            let (preview_rel, display_rel) = self
+                .generate_image_derivatives(upload_id, &original, mime_type)
+                .await?;
             Upload::set_preview_path(&self.pool, upload_id, &preview_rel).await?;
-            tracing::info!("preview generated for upload {upload_id}");
+            Upload::set_display_path(&self.pool, upload_id, &display_rel).await?;
+            Upload::set_derivatives_rev(&self.pool, upload_id, Self::DERIVATIVES_REV).await?;
+            tracing::info!("preview + display generated for upload {upload_id}");
         } else if mime_type.starts_with("video/") {
-            let thumb_rel = self.generate_video_thumbnail(upload_id, &original).await?;
-            Upload::set_thumbnail_path(&self.pool, upload_id, &thumb_rel).await?;
-            tracing::info!("thumbnail generated for upload {upload_id}");
+            // A missing poster must NOT fail the upload. `set_thumbnail_path` is only reached when
+            // a file really exists, so `thumbnail_path` stays NULL otherwise — which every consumer
+            // already handles (FeedListCard, VirtualFeed, LightboxModal are all null-safe).
+            //
+            // The `?` here used to hide the defect; making the check strict without also making
+            // this non-fatal would have been far worse than the bug. Every clip of a second or less
+            // would fail compression, exhaust its retries and be soft-deleted — a cosmetic defect
+            // turned into data loss, on exactly the mis-tap/Live-Photo clips guests produce most.
+            match self.generate_video_thumbnail(upload_id, &original).await? {
+                Some(thumb_rel) => {
+                    Upload::set_thumbnail_path(&self.pool, upload_id, &thumb_rel).await?;
+                    tracing::info!("thumbnail generated for upload {upload_id}");
+                }
+                None => {
+                    tracing::warn!(
+                        %upload_id,
+                        "no poster frame could be extracted; the video keeps its own tile"
+                    );
+                }
+            }
         }
 
         Upload::set_compression_status(&self.pool, upload_id, "done").await?;
         Ok(())
     }
 
-    async fn generate_image_preview(
+    /// Longest edge of the big-screen "display" derivative used by the diashow. Sized to be
+    /// sharp on 1080p/4K while staying bounded (a ~2048px JPEG decodes to ~16 MB — trivial
+    /// for any kiosk, unlike a raw multi-thousand-pixel original).
+    const DISPLAY_MAX_EDGE: u32 = 2048;
+    /// Longest edge of the phone-feed "preview" (data-saver default).
+    const PREVIEW_MAX_EDGE: u32 = 800;
+
+    /// Above this pixel count the PNG original is stored as uploaded, unoptimised.
+    ///
+    /// oxipng's peak memory scales with PIXELS, not file size: it decodes the PNG itself and
+    /// then evaluates row filters, each trial holding a full-size buffer. That is why a 2.82
+    /// MiB file could measure 1250 MiB of peak RSS inside a 1 GiB container — smooth,
+    /// synthetic content compresses to almost nothing on disk while still being 8000x8000.
+    /// 8 MP covers every real phone photo; beyond it we decline the (lossless, cosmetic)
+    /// saving rather than risk the OOM kill.
+    const OXIPNG_MAX_PIXELS: u64 = 8_000_000;
+
+    /// Estimated peak heap above which an image job takes the exclusive `heavy` permit.
+    ///
+    /// `compression_concurrency` (default 2) bounds how many jobs run at once, but says
+    /// nothing about how much memory each one costs, and the container gets 1 GiB total. A
+    /// single 8000x8000 original measures ~516 MiB peak even with the decode correctly scoped
+    /// — two of those overlapping is 1032 MiB and another OOM kill, from nothing more exotic
+    /// than two guests uploading big photos at the same moment.
+    ///
+    /// 150 MiB sits far above a normal phone photo (a 12 MP JPEG costs ~50 MiB all-in) so the
+    /// common path never serialises, and far below the point where two jobs stop fitting.
+    /// Throughput is unaffected for everything except the rare giant, which is exactly the
+    /// case that must not run in parallel with another giant.
+    const HEAVY_IMAGE_BYTES: u64 = 150 * 1024 * 1024;
+
+    /// Wall-clock ceiling for one oxipng run.
+    ///
+    /// Bounds TIME, NOT MEMORY — oxipng checks the deadline between trials, so a single trial
+    /// still allocates in full. The pixel gate above and the sequential build (see
+    /// `default-features = false` in Cargo.toml) are what bound memory. Do not treat this
+    /// constant as the OOM fix.
+    const OXIPNG_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(20);
+
+    /// Decode the image ONCE and emit both derivatives — the 800px `preview` (phone feed)
+    /// and the 2048px `display` (diashow). Returns `(preview_rel, display_rel)`.
+    async fn generate_image_derivatives(
         &self,
         upload_id: Uuid,
         original: &Path,
         mime_type: &str,
-    ) -> Result<String> {
+    ) -> Result<(String, String)> {
         let previews_dir = self.media_path.join("previews");
+        let displays_dir = self.media_path.join("displays");
         tokio::fs::create_dir_all(&previews_dir).await?;
+        tokio::fs::create_dir_all(&displays_dir).await?;
 
-        let preview_filename = format!("{upload_id}.jpg");
-        let preview_path = previews_dir.join(&preview_filename);
+        let filename = format!("{upload_id}.jpg");
+        let preview_path = previews_dir.join(&filename);
+        let display_path = displays_dir.join(&filename);
         let original = original.to_path_buf();
-        let preview_path_clone = preview_path.clone();
         let mime_owned = mime_type.to_string();
 
-        // Run blocking image operations in a spawn_blocking task
-        tokio::task::spawn_blocking(move || -> Result<()> {
-            // Reject decompression bombs *before* fully decoding: the upload body
-            // cap bounds the file size on disk, but a small file can still decode to
-            // enormous dimensions (e.g. a ~1 MB image expanding to 50k×50k px →
-            // gigabytes), OOM-ing the box during decode/resize. 12000×12000 covers
-            // any real phone photo; max_alloc hard-caps the decode allocation.
-            let mut reader = image::ImageReader::open(&original)
-                .context("failed to open image")?
-                .with_guessed_format()
-                .context("failed to read image header")?;
-            let mut limits = image::Limits::default();
-            limits.max_image_width = Some(12_000);
-            limits.max_image_height = Some(12_000);
-            limits.max_alloc = Some(256 * 1024 * 1024);
-            reader.limits(limits);
-            let img = reader.decode().context("failed to decode image")?;
-
-            // Resize to max 800px wide, preserving aspect ratio
-            let preview = img.resize(800, 800, image::imageops::FilterType::Lanczos3);
-            preview.save_with_format(&preview_path_clone, image::ImageFormat::Jpeg)
-                .context("failed to save preview")?;
-
-            // If the original is PNG, try lossless compression in-place
-            if mime_owned == "image/png" {
-                let opts = oxipng::Options::from_preset(2);
-                let _ = oxipng::optimize(
-                    &oxipng::InFile::Path(original),
-                    &oxipng::OutFile::Path {
-                        path: None,
-                        preserve_attrs: true,
-                    },
-                    &opts,
+        // Estimate the peak from the HEADER (no pixels decoded — the same kind of cheap probe
+        // the upload handler already does via `exceeds_decode_budget`) and, if this job is a
+        // giant, take the exclusive permit so it cannot overlap another giant. Held for the
+        // whole blocking section, released on drop including on error.
+        let estimate =
+            crate::services::imaging::estimated_processing_peak_bytes(&original, Self::DISPLAY_MAX_EDGE);
+        let _heavy_permit = match estimate {
+            Some(bytes) if bytes > Self::HEAVY_IMAGE_BYTES => {
+                tracing::debug!(
+                    %upload_id,
+                    estimated_mib = bytes / (1024 * 1024),
+                    "waiting for the heavy-image permit"
                 );
+                Some(self.heavy.acquire().await)
             }
+            _ => None,
+        };
 
-            Ok(())
+        // Run blocking image operations in a spawn_blocking task
+        tokio::task::spawn_blocking(move || {
+            write_image_derivatives(upload_id, &original, &mime_owned, &preview_path, &display_path)
         })
         .await??;
 
-        Ok(format!("previews/{preview_filename}"))
+        Ok((
+            format!("previews/{filename}"),
+            format!("displays/{filename}"),
+        ))
     }
 
+    /// Regenerate image derivatives that an older pipeline produced. Fire-and-forget from
+    /// startup; picks up two cases, both of which leave the ORIGINAL untouched:
+    ///
+    /// - uploads processed before the `display` derivative existed (preview but no
+    ///   `display_path`), and
+    /// - uploads whose derivatives predate `DERIVATIVES_REV` — currently rev 1, which applies
+    ///   the EXIF orientation. Everything generated before it is stored sideways for any
+    ///   portrait phone photo.
+    ///
+    /// Unlike the failure path in `process`, a backfill error is logged and skipped — it must
+    /// NEVER destroy or soft-delete an upload that already has a working preview.
+    ///
+    /// Bounded in three ways, all of them load-bearing on a box that restarts itself:
+    /// `derivative_attempts` stops a fatal row being replayed on every boot, `BACKFILL_BATCH`
+    /// stops one start queueing unbounded work, and the whole thing runs as ONE task walking
+    /// the rows sequentially rather than N tasks racing for the same semaphore.
+    pub async fn backfill_stale_derivatives(&self) {
+        // `original_path IS NOT NULL` was dead — the column is NOT NULL. What actually needs
+        // excluding is the blanked path `cleanup_deleted_media` leaves behind.
+        let rows = sqlx::query_as::<_, (Uuid, String, String)>(
+            "SELECT id, original_path, mime_type FROM upload
+             WHERE deleted_at IS NULL AND mime_type LIKE 'image/%'
+               AND original_path <> ''
+               AND derivative_attempts < $2
+               AND (
+                     (display_path IS NULL AND preview_path IS NOT NULL)
+                  OR derivatives_rev < $1
+               )
+             ORDER BY created_at DESC
+             LIMIT $3",
+        )
+        .bind(Self::DERIVATIVES_REV)
+        .bind(Self::MAX_DERIVATIVE_ATTEMPTS)
+        .bind(Self::BACKFILL_BATCH)
+        .fetch_all(&self.pool)
+        .await;
+        let rows = match rows {
+            Ok(r) => r,
+            Err(e) => {
+                tracing::warn!(error = ?e, "derivative backfill query failed");
+                return;
+            }
+        };
+
+        self.report_exhausted_derivatives().await;
+
+        if rows.is_empty() {
+            return;
+        }
+        tracing::info!("regenerating derivatives for {} upload(s)", rows.len());
+
+        // ONE task for the whole batch. The previous shape spawned a task per row, so a large
+        // backlog created thousands of live tasks that each held a pool handle and queued on
+        // the same two semaphore permits, competing with live uploads for the entire boot.
+        let worker = self.clone();
+        tokio::spawn(async move {
+            for (id, original_path, mime_type) in rows {
+                let _permit = worker.semaphore.acquire().await;
+                // Write-ahead, exactly as in the live path: if this row is the one that kills
+                // the process, this increment is the only thing that outlives the SIGKILL.
+                match Upload::begin_derivative_attempt(&worker.pool, id).await {
+                    Ok(Some(n)) if n > Self::MAX_DERIVATIVE_ATTEMPTS => continue,
+                    Ok(Some(_)) => {}
+                    Ok(None) => continue,
+                    Err(e) => {
+                        tracing::warn!(error = ?e, %id, "could not record a backfill attempt; skipping");
+                        continue;
+                    }
+                }
+                let original = worker.media_path.join(&original_path);
+                match worker
+                    .generate_image_derivatives(id, &original, &mime_type)
+                    .await
+                {
+                    Ok((preview_rel, display_rel)) => {
+                        let _ = Upload::set_preview_path(&worker.pool, id, &preview_rel).await;
+                        let _ = Upload::set_display_path(&worker.pool, id, &display_rel).await;
+                        // Clears derivative_attempts too, so a row that failed transiently is
+                        // not one boot closer to being abandoned.
+                        let _ =
+                            Upload::set_derivatives_rev(&worker.pool, id, Self::DERIVATIVES_REV)
+                                .await;
+                        tracing::info!("derivatives regenerated for upload {id}");
+                    }
+                    Err(e) => {
+                        // Leave the existing derivatives and the original intact; this row is
+                        // retried on the next start until its attempt budget runs out. The rev
+                        // stays behind, which is the marker that it still needs doing.
+                        tracing::warn!(error = ?e, %id, "derivative backfill failed; leaving as-is");
+                        let _ =
+                            Upload::record_derivative_failure(&worker.pool, id, &format!("{e:#}"))
+                                .await;
+                    }
+                }
+            }
+        });
+    }
+
+    /// Re-extract poster frames for videos that never got one.
+    ///
+    /// A video interrupted by a restart is stranded: `startup_recovery` flips its
+    /// `compression_status` from `processing` to `failed` and nothing re-enqueues it, so
+    /// `thumbnail_path` stays NULL forever while the clip itself plays fine. The feed shows a
+    /// posterless tile for the rest of the event, and after
+    /// `FAILED_ORIGINAL_RETENTION_DAYS` the reclaim sweep is entitled to the original.
+    ///
+    /// Shares `derivative_attempts` with the image backfill on purpose. Note the consequence,
+    /// which is intended rather than a bug to fix later: `extract_poster_frame` returning
+    /// `Ok(false)` is a NORMAL, permanent outcome for a sub-second clip (Live Photos,
+    /// mis-taps), and since the counter is write-ahead and only cleared by a real success,
+    /// those clips stop being re-ffmpeg'd on every boot once the budget is spent.
+    pub async fn backfill_video_posters(&self) {
+        let rows = sqlx::query_as::<_, (Uuid, String)>(
+            "SELECT id, original_path FROM upload
+             WHERE deleted_at IS NULL AND mime_type LIKE 'video/%'
+               AND thumbnail_path IS NULL
+               AND original_path <> ''
+               AND derivative_attempts < $1
+             ORDER BY created_at DESC
+             LIMIT $2",
+        )
+        .bind(Self::MAX_DERIVATIVE_ATTEMPTS)
+        .bind(Self::BACKFILL_BATCH)
+        .fetch_all(&self.pool)
+        .await;
+        let rows = match rows {
+            Ok(r) => r,
+            Err(e) => {
+                tracing::warn!(error = ?e, "video poster backfill query failed");
+                return;
+            }
+        };
+        if rows.is_empty() {
+            return;
+        }
+        tracing::info!("re-extracting posters for {} video(s)", rows.len());
+
+        let worker = self.clone();
+        tokio::spawn(async move {
+            for (id, original_path) in rows {
+                let _permit = worker.semaphore.acquire().await;
+                match Upload::begin_derivative_attempt(&worker.pool, id).await {
+                    Ok(Some(n)) if n > Self::MAX_DERIVATIVE_ATTEMPTS => continue,
+                    Ok(Some(_)) => {}
+                    Ok(None) => continue,
+                    Err(e) => {
+                        tracing::warn!(error = ?e, %id, "could not record a poster attempt; skipping");
+                        continue;
+                    }
+                }
+                let original = worker.media_path.join(&original_path);
+                match worker.generate_video_thumbnail(id, &original).await {
+                    Ok(Some(thumb_rel)) => {
+                        if Upload::set_thumbnail_path(&worker.pool, id, &thumb_rel)
+                            .await
+                            .is_ok()
+                        {
+                            // Clears the attempt counter: a video that eventually succeeded
+                            // must not carry a budget scar into a future pipeline revision.
+                            let _ = Upload::set_derivatives_rev(
+                                &worker.pool,
+                                id,
+                                Self::DERIVATIVES_REV,
+                            )
+                            .await;
+                            tracing::info!("poster regenerated for upload {id}");
+                        }
+                    }
+                    // No frame at all — normal for a very short clip. The tile stays
+                    // posterless and the attempt is spent, which is what stops the retry.
+                    Ok(None) => {
+                        tracing::debug!(%id, "still no poster frame; leaving the tile as-is");
+                    }
+                    Err(e) => {
+                        tracing::warn!(error = ?e, %id, "poster backfill failed; leaving as-is");
+                        let _ =
+                            Upload::record_derivative_failure(&worker.pool, id, &format!("{e:#}"))
+                                .await;
+                    }
+                }
+            }
+        });
+    }
+
+    /// Say out loud, once per boot, that some uploads have stopped being retried.
+    ///
+    /// Without this the give-up is invisible: the loop stops (which is the point) but the
+    /// affected photos keep a stale or missing derivative forever with nothing to notice. The
+    /// originals are untouched, so this is recoverable once the cause is fixed — reset
+    /// `derivative_attempts` to 0 and restart.
+    async fn report_exhausted_derivatives(&self) {
+        let exhausted: Result<i64, _> = sqlx::query_scalar(
+            "SELECT count(*) FROM upload
+             WHERE deleted_at IS NULL AND mime_type LIKE 'image/%'
+               AND derivative_attempts >= $2
+               AND (
+                     (display_path IS NULL AND preview_path IS NOT NULL)
+                  OR derivatives_rev < $1
+               )",
+        )
+        .bind(Self::DERIVATIVES_REV)
+        .bind(Self::MAX_DERIVATIVE_ATTEMPTS)
+        .fetch_one(&self.pool)
+        .await;
+        if let Ok(count) = exhausted
+            && count > 0
+        {
+            tracing::error!(
+                count,
+                "{count} upload(s) exhausted derivative regeneration and will no longer be \
+                 retried; their originals are intact — see upload.derivative_last_error, fix \
+                 the cause, then reset derivative_attempts to 0 and restart"
+            );
+        }
+    }
+
+    /// Extract the feed poster for a video. `Ok(None)` when the clip yields no frame — see
+    /// [`crate::services::video::extract_poster_frame`], which owns the seek order, the timeout and
+    /// the artifact check that this function used to be missing.
     async fn generate_video_thumbnail(
         &self,
         upload_id: Uuid,
         original: &Path,
-    ) -> Result<String> {
+    ) -> Result<Option<String>> {
         let thumbs_dir = self.media_path.join("thumbnails");
         tokio::fs::create_dir_all(&thumbs_dir).await?;
 
         let thumb_filename = format!("{upload_id}.jpg");
         let thumb_path = thumbs_dir.join(&thumb_filename);
 
-        // Hard timeout — a malformed video can hang `ffmpeg` indefinitely. Without a
-        // cap, the held compression-worker semaphore permit is never released and the
-        // pool eventually deadlocks (no further uploads ever processed). 120s is well
-        // above the time to extract one frame from any sane input.
-        let mut child = tokio::process::Command::new("ffmpeg")
-            .args([
-                "-i",
-                original.to_str().unwrap_or_default(),
-                "-vframes",
-                "1",
-                "-ss",
-                "00:00:01",
-                "-vf",
-                "scale=800:-1",
-                "-y",
-                thumb_path.to_str().unwrap_or_default(),
-            ])
-            .stdout(std::process::Stdio::piped())
-            .stderr(std::process::Stdio::piped())
-            .kill_on_drop(true)
-            .spawn()
-            .context("failed to spawn ffmpeg")?;
+        let produced =
+            crate::services::video::extract_poster_frame(original, &thumb_path, 800).await?;
 
-        let status = match tokio::time::timeout(
-            std::time::Duration::from_secs(120),
-            child.wait(),
-        )
-        .await
-        {
-            Ok(res) => res.context("ffmpeg wait failed")?,
-            Err(_) => {
-                let _ = child.kill().await;
-                anyhow::bail!("ffmpeg timeout after 120s");
-            }
-        };
-
-        if !status.success() {
-            // Best-effort: drain stderr for the log.
-            let mut stderr = Vec::new();
-            if let Some(mut handle) = child.stderr.take() {
-                use tokio::io::AsyncReadExt;
-                let _ = handle.read_to_end(&mut stderr).await;
-            }
-            anyhow::bail!(
-                "ffmpeg failed: {}",
-                String::from_utf8_lossy(&stderr)
-            );
-        }
-
-        Ok(format!("thumbnails/{thumb_filename}"))
+        Ok(produced.then(|| format!("thumbnails/{thumb_filename}")))
+    }
+}
+
+/// The blocking half of [`CompressionWorker::generate_image_derivatives`]: decode once, write
+/// both derivatives, then optionally shrink a PNG original in place.
+///
+/// A free function rather than an inline closure so its memory behaviour is directly testable —
+/// this is the code path that OOM-killed the container, and the fix is a scoping property that a
+/// future edit could silently undo.
+fn write_image_derivatives(
+    upload_id: Uuid,
+    original: &Path,
+    mime_type: &str,
+    preview_path: &Path,
+    display_path: &Path,
+) -> Result<()> {
+    let preview_max = CompressionWorker::PREVIEW_MAX_EDGE;
+    let display_max = CompressionWorker::DISPLAY_MAX_EDGE;
+
+    // THE FULL-SIZE DECODE IS SCOPED TO THIS BLOCK ON PURPOSE, and the block yields the
+    // DISPLAY derivative rather than the original.
+    //
+    // `img` is up to 256 MiB (imaging::decode_limits max_alloc) and `resize` only BORROWS it,
+    // so it used to stay alive through both resizes AND the oxipng call below — which decodes
+    // the PNG a second time and holds a full-size buffer per filter trial. That measured
+    // ~1250 MiB of peak RSS for a 2.8 MiB input, inside a 1 GiB cgroup: the container was
+    // SIGKILLed, taking every SSE stream and every in-flight upload with it.
+    //
+    // A block rather than a bare `drop(img)` because a `drop` call is one careless edit away
+    // from being removed as redundant-looking — and note the `else` arm MOVES `img` out, which
+    // is what makes "the block's value is the only survivor" true in both arms.
+    let (display, width, height) = {
+        // Decompression-bomb limits + EXIF orientation, both in one place — see
+        // services::imaging for why neither may be skipped.
+        let img = crate::services::imaging::decode_oriented(original)?;
+        let (width, height) = (img.width(), img.height());
+
+        // Display: max 2048px for the diashow. Only DOWNSCALE — never upscale a smaller
+        // original (that adds bytes with no quality gain); re-encode it as JPEG as-is.
+        let display = if width > display_max || height > display_max {
+            img.resize(
+                display_max,
+                display_max,
+                image::imageops::FilterType::Lanczos3,
+            )
+        } else {
+            img
+        };
+        (display, width, height)
+    };
+
+    display
+        .save_with_format(display_path, image::ImageFormat::Jpeg)
+        .context("failed to save display")?;
+
+    // Preview: max 800px, derived from the DISPLAY, not from the original.
+    //
+    // Both derivatives used to resize the full-size decode independently, so a 8000x8000
+    // original paid for two full-size Lanczos passes and their intermediates — measured 520
+    // MiB peak even after the scoping fix above, which two concurrent workers cannot fit in a
+    // 1 GiB container. Chaining 8000 -> 2048 -> 800 makes the second pass operate on 2048px
+    // input, and the full-size buffer is already freed by the time it runs. Quality is not the
+    // trade-off here: a staged Lanczos3 downscale to 800px is visually indistinguishable from
+    // a single-step one (and is a standard technique for large ratios).
+    display
+        .resize(
+            preview_max,
+            preview_max,
+            image::imageops::FilterType::Lanczos3,
+        )
+        .save_with_format(preview_path, image::ImageFormat::Jpeg)
+        .context("failed to save preview")?;
+    drop(display);
+
+    let pixels = u64::from(width) * u64::from(height);
+
+    // If the original is PNG, try lossless compression in place — but only when its pixel count
+    // is inside the budget, and never for longer than OXIPNG_TIMEOUT. This is a best-effort size
+    // saving: declining it costs disk, while attempting it unbounded cost the whole container.
+    if mime_type == "image/png" {
+        if pixels <= CompressionWorker::OXIPNG_MAX_PIXELS {
+            let mut opts = oxipng::Options::from_preset(2);
+            opts.timeout = Some(CompressionWorker::OXIPNG_TIMEOUT);
+            let _ = oxipng::optimize(
+                &oxipng::InFile::Path(original.to_path_buf()),
+                &oxipng::OutFile::Path {
+                    path: None,
+                    preserve_attrs: true,
+                },
+                &opts,
+            );
+        } else {
+            tracing::info!(
+                %upload_id, pixels,
+                "skipping oxipng: above the pixel budget; the original is stored as uploaded"
+            );
+        }
+    }
+
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// Peak resident set of THIS process, in bytes, from `/proc/self/status`.
+    fn peak_rss_bytes() -> u64 {
+        let status = std::fs::read_to_string("/proc/self/status").expect("procfs");
+        let line = status
+            .lines()
+            .find(|l| l.starts_with("VmHWM:"))
+            .expect("VmHWM");
+        let kb: u64 = line
+            .split_whitespace()
+            .nth(1)
+            .and_then(|v| v.parse().ok())
+            .expect("VmHWM value");
+        kb * 1024
+    }
+
+    /// Reset the kernel's peak-RSS watermark so the measurement covers only what follows.
+    /// Linux 4.0+; writing "5" to `clear_refs` resets `VmHWM` to the current RSS.
+    fn reset_peak_rss() {
+        let _ = std::fs::write("/proc/self/clear_refs", "5");
+    }
+
+    /// The pixel gate has to sit below what the axis limits allow, or it can never fire.
+    #[test]
+    fn the_oxipng_gate_is_reachable_within_the_decode_limits() {
+        const _: () = {
+            // imaging::decode_limits permits 12_000 x 12_000 = 144 MP. A gate above that would
+            // never skip anything.
+            assert!(CompressionWorker::OXIPNG_MAX_PIXELS < 12_000 * 12_000);
+            // ...and it must stay above a 48 MP camera, so real photos still get optimised.
+            assert!(CompressionWorker::OXIPNG_MAX_PIXELS >= 8_000_000);
+        };
+    }
+
+    /// The heavy-image gate has to classify the two cases the way the sizing assumed:
+    /// an ordinary phone photo must NOT serialise, and the giant must.
+    #[test]
+    fn the_heavy_gate_separates_a_phone_photo_from_a_giant() {
+        let dir = std::env::temp_dir().join(format!("es-heavy-{}", std::process::id()));
+        std::fs::create_dir_all(&dir).unwrap();
+
+        // 12 MP, the shape of a default phone capture.
+        let ordinary = dir.join("ordinary.jpg");
+        image::RgbImage::new(4032, 3024).save(&ordinary).unwrap();
+        let ordinary_peak = crate::services::imaging::estimated_processing_peak_bytes(
+            &ordinary,
+            CompressionWorker::DISPLAY_MAX_EDGE,
+        )
+        .expect("header readable");
+        assert!(
+            ordinary_peak <= CompressionWorker::HEAVY_IMAGE_BYTES,
+            "a 12 MP photo estimated at {} MiB would serialise the common path",
+            ordinary_peak / 1048576
+        );
+
+        // The 64 MP RGBA case that measured ~516 MiB peak.
+        let giant = dir.join("giant.png");
+        image::RgbaImage::new(8000, 8000).save(&giant).unwrap();
+        let giant_peak = crate::services::imaging::estimated_processing_peak_bytes(
+            &giant,
+            CompressionWorker::DISPLAY_MAX_EDGE,
+        )
+        .expect("header readable");
+        assert!(
+            giant_peak > CompressionWorker::HEAVY_IMAGE_BYTES,
+            "an 8000x8000 RGBA original estimated at only {} MiB would be allowed to run \
+             concurrently with another one — 2x its real ~516 MiB peak does not fit in 1 GiB",
+            giant_peak / 1048576
+        );
+        // The estimate must also be in the right ballpark, not merely on the right side of the
+        // threshold: 244 MiB decode + 262 MiB f32 resize intermediate.
+        assert!(
+            (400..700).contains(&(giant_peak / 1048576)),
+            "estimate {} MiB is far from the measured ~516 MiB peak",
+            giant_peak / 1048576
+        );
+
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
+    /// The OOM that took the container down, measured rather than argued.
+    ///
+    /// An 8000x8000 RGBA PNG passes admission: 256,000,000 bytes is just under the 256 MiB
+    /// `max_alloc`, and smooth content is a few MB on disk, far under any size cap. The old
+    /// code kept that ~244 MiB decode alive across an unbounded, multi-threaded oxipng run and
+    /// peaked at ~1250 MiB — inside a 1 GiB cgroup. Being SIGKILLed there is not a blip: the
+    /// row was already committed, so the boot backfill replayed the identical workload on every
+    /// restart.
+    ///
+    /// `#[ignore]` because it allocates ~250 MiB and takes a few seconds. Run explicitly:
+    ///   cargo test --release oom -- --ignored --nocapture --test-threads=1
+    /// It must run ALONE — `VmHWM` is per process, so a concurrent test would pollute it.
+    #[test]
+    #[ignore = "heavy: allocates ~250 MiB; run with --ignored --test-threads=1"]
+    fn a_large_png_stays_far_below_the_container_limit() {
+        const EDGE: u32 = 8_000;
+        let dir = std::env::temp_dir().join(format!("es-oom-{}", std::process::id()));
+        std::fs::create_dir_all(&dir).unwrap();
+        let original = dir.join("big.png");
+
+        // Smooth gradient: ~244 MiB decoded, a couple of MB on disk. That gap is the whole
+        // point — file size tells you nothing about what a PNG costs to process.
+        {
+            let mut buf = image::RgbaImage::new(EDGE, EDGE);
+            for (x, y, px) in buf.enumerate_pixels_mut() {
+                *px = image::Rgba([(x >> 5) as u8, (y >> 5) as u8, ((x + y) >> 6) as u8, 255]);
+            }
+            buf.save(&original).unwrap();
+        }
+
+        // Everything above is fixture setup, not the code under test.
+        reset_peak_rss();
+        let before = peak_rss_bytes();
+
+        write_image_derivatives(
+            Uuid::new_v4(),
+            &original,
+            "image/png",
+            &dir.join("preview.jpg"),
+            &dir.join("display.jpg"),
+        )
+        .expect("derivatives");
+
+        let peak = peak_rss_bytes();
+        let on_disk = std::fs::metadata(&original).unwrap().len();
+        eprintln!(
+            "input {:.2} MiB on disk ({EDGE}x{EDGE}); peak RSS {:.0} MiB (was {:.0} MiB before)",
+            on_disk as f64 / 1048576.0,
+            peak as f64 / 1048576.0,
+            before as f64 / 1048576.0
+        );
+
+        assert!(dir.join("preview.jpg").exists() && dir.join("display.jpg").exists());
+        // The container gets 1 GiB and runs two of these concurrently. 600 MiB is a generous
+        // ceiling that the old code (~1250 MiB) could not have met.
+        assert!(
+            peak < 600 * 1024 * 1024,
+            "peak RSS {} MiB — the decode is being held across oxipng again, or the pixel \
+             gate stopped firing",
+            peak / 1048576
+        );
+        let _ = std::fs::remove_dir_all(&dir);
     }
 }

backend/src/services/config.rs

@@ -1,46 +1,147 @@
-//! Reads of the runtime-tunable `config` table.
+//! Reads of the runtime-tunable `config` table, fronted by an in-memory cache.
 //!
 //! Each handler used to keep a small local copy of these helpers; consolidating them
 //! here means one place to add a parser, one place to mock for tests, and one place to
 //! find when a key changes. New keys do not require code changes — they're picked up
-//! the next time someone calls `get_*`.
+//! the next time the cache reloads.
+//!
+//! ## Why a cache
+//!
+//! The `config` table is effectively static during an event, yet it was the busiest
+//! query in the system: every request re-read each key with its own `SELECT`
+//! (an upload touched it ~8 times). Against the small connection pool that was the
+//! throughput ceiling. [`ConfigCache`] loads the whole table once and serves reads
+//! from memory.
+//!
+//! ## Consistency contract
+//!
+//! Correctness comes from **synchronous invalidation on every write**, not from the
+//! TTL. The two runtime write paths — the admin `PATCH /admin/config` handler and the
+//! test-mode truncate/reseed — both call [`ConfigCache::invalidate`] after committing,
+//! so the *next* read reloads from the DB and sees the new value immediately. The
+//! [`RELOAD_TTL`] is only a safety net for out-of-band changes (e.g. a migration or a
+//! manual DB edit); it is deliberately short but never the primary mechanism.
 //!
 //! Values are read with a default fallback so the app still starts if a key is missing
 //! (e.g. during a migration window). Production seeds keys via migrations 005 and 009.
 
+use std::collections::HashMap;
+use std::sync::{Arc, RwLock};
+use std::time::{Duration, Instant};
+
 use sqlx::PgPool;
 
-async fn fetch_raw(pool: &PgPool, key: &str) -> Option<String> {
-    sqlx::query_as::<_, (String,)>("SELECT value FROM config WHERE key = $1")
-        .bind(key)
-        .fetch_optional(pool)
+/// How long a loaded snapshot is trusted before the next read reloads it. This is a
+/// backstop for out-of-band DB changes only — every in-process write invalidates the
+/// cache synchronously, so tests that PATCH-then-assert never depend on this expiring.
+const RELOAD_TTL: Duration = Duration::from_secs(30);
+
+struct Snapshot {
+    values: HashMap<String, String>,
+    loaded_at: Instant,
+}
+
+/// In-memory cache of the entire `config` table. Cheap to `clone` (shares the pool and
+/// the `Arc`), so it lives in `AppState` and every handler reads through it.
+#[derive(Clone)]
+pub struct ConfigCache {
+    pool: PgPool,
+    inner: Arc<RwLock<Option<Snapshot>>>,
+}
+
+impl ConfigCache {
+    pub fn new(pool: PgPool) -> Self {
+        Self {
+            pool,
+            inner: Arc::new(RwLock::new(None)),
+        }
+    }
+
+    /// Drop the cached snapshot so the next read reloads the whole table from the DB.
+    /// Call this after any write to the `config` table (admin PATCH, test reseed).
+    pub fn invalidate(&self) {
+        *self.inner.write().unwrap() = None;
+    }
+
+    /// Return the fresh snapshot if one is loaded and still within [`RELOAD_TTL`].
+    fn fresh_snapshot(&self) -> Option<HashMap<String, String>> {
+        let guard = self.inner.read().unwrap();
+        match guard.as_ref() {
+            Some(snap) if snap.loaded_at.elapsed() < RELOAD_TTL => Some(snap.values.clone()),
+            _ => None,
+        }
+    }
+
+    /// Read one key, loading the whole table into the cache on a miss/expiry. On a DB
+    /// error we return `None` (callers fall back to their default) without poisoning
+    /// the cache.
+    async fn get_raw(&self, key: &str) -> Option<String> {
+        if let Some(values) = self.fresh_snapshot() {
+            return values.get(key).cloned();
+        }
+
+        // Cache miss or stale — reload the entire table in one query.
+        let rows: Vec<(String, String)> = match sqlx::query_as::<_, (String, String)>(
+            "SELECT key, value FROM config",
+        )
+        .fetch_all(&self.pool)
         .await
-        .ok()
-        .flatten()
-        .map(|(v,)| v)
+        {
+            Ok(rows) => rows,
+            Err(e) => {
+                tracing::warn!(error = ?e, "config reload failed; using defaults for this read");
+                return None;
+            }
+        };
+
+        let values: HashMap<String, String> = rows.into_iter().collect();
+        let result = values.get(key).cloned();
+        *self.inner.write().unwrap() = Some(Snapshot {
+            values,
+            loaded_at: Instant::now(),
+        });
+        result
+    }
 }
 
-pub async fn get_str(pool: &PgPool, key: &str, default: &str) -> String {
-    fetch_raw(pool, key).await.unwrap_or_else(|| default.to_string())
+pub async fn get_str(cache: &ConfigCache, key: &str, default: &str) -> String {
+    cache
+        .get_raw(key)
+        .await
+        .unwrap_or_else(|| default.to_string())
 }
 
-pub async fn get_i64(pool: &PgPool, key: &str, default: i64) -> i64 {
-    fetch_raw(pool, key).await.and_then(|v| v.parse().ok()).unwrap_or(default)
+pub async fn get_i64(cache: &ConfigCache, key: &str, default: i64) -> i64 {
+    cache
+        .get_raw(key)
+        .await
+        .and_then(|v| v.parse().ok())
+        .unwrap_or(default)
 }
 
-pub async fn get_usize(pool: &PgPool, key: &str, default: usize) -> usize {
-    fetch_raw(pool, key).await.and_then(|v| v.parse().ok()).unwrap_or(default)
+pub async fn get_usize(cache: &ConfigCache, key: &str, default: usize) -> usize {
+    cache
+        .get_raw(key)
+        .await
+        .and_then(|v| v.parse().ok())
+        .unwrap_or(default)
 }
 
-pub async fn get_f64(pool: &PgPool, key: &str, default: f64) -> f64 {
-    fetch_raw(pool, key).await.and_then(|v| v.parse().ok()).unwrap_or(default)
+pub async fn get_f64(cache: &ConfigCache, key: &str, default: f64) -> f64 {
+    cache
+        .get_raw(key)
+        .await
+        .and_then(|v| v.parse().ok())
+        .unwrap_or(default)
 }
 
 /// Parses common truthy spellings used by both the migration seeds and the admin form.
 /// Accepts `true/false`, `1/0`, `yes/no`, `on/off` — case-insensitive. Anything else
 /// returns `default`.
-pub async fn get_bool(pool: &PgPool, key: &str, default: bool) -> bool {
-    let Some(raw) = fetch_raw(pool, key).await else { return default };
+pub async fn get_bool(cache: &ConfigCache, key: &str, default: bool) -> bool {
+    let Some(raw) = cache.get_raw(key).await else {
+        return default;
+    };
     match raw.trim().to_ascii_lowercase().as_str() {
         "true" | "1" | "yes" | "on" => true,
         "false" | "0" | "no" | "off" => false,

backend/src/services/disk.rs

@@ -0,0 +1,169 @@
+//! Cached view of the filesystem backing the media directory.
+//!
+//! Free/total disk space is needed on two hot paths — the per-user storage quota
+//! (checked on every upload *and* every `GET /me/quota` poll) and the admin stats
+//! endpoint. Reading it means `sysinfo::Disks::new_with_refreshed_list()`, which stats
+//! every mounted filesystem; doing that per request is wasteful for a number that
+//! barely moves. [`DiskCache`] refreshes it at most once per [`TTL`] and serves the
+//! rest from memory.
+
+use std::path::{Path, PathBuf};
+use std::sync::{Arc, RwLock};
+use std::time::{Duration, Instant};
+
+/// How long a disk reading is trusted before the next call re-stats the filesystem.
+const TTL: Duration = Duration::from_secs(15);
+
+#[derive(Clone, Copy)]
+pub struct DiskInfo {
+    pub total: u64,
+    pub free: u64,
+}
+
+/// Cheap-to-clone cache of the media filesystem's total/free bytes. Lives in
+/// `AppState`.
+#[derive(Clone)]
+pub struct DiskCache {
+    inner: Arc<RwLock<Option<(PathBuf, DiskInfo, Instant)>>>,
+}
+
+impl DiskCache {
+    pub fn new() -> Self {
+        Self {
+            inner: Arc::new(RwLock::new(None)),
+        }
+    }
+
+    /// Drop the cached reading so the next `snapshot()` re-measures the filesystem.
+    ///
+    /// Used by the e2e TRUNCATE endpoint. Truncating deletes every uploaded file, which materially
+    /// changes free space — but the cached reading survives for up to the TTL, so the next test can
+    /// compute a quota from the PREVIOUS test's disk. That matters now that the quota tests steer
+    /// the per-user limit off `free_disk_bytes`: a stale reading makes the limit wrong and the test
+    /// flaky, for reasons that have nothing to do with the code under test.
+    pub fn invalidate(&self) {
+        *self.inner.write().unwrap() = None;
+    }
+
+    /// Cached `(total, free)` bytes for the filesystem that holds `media_path`.
+    ///
+    /// Returns `None` when the mount can't be resolved — callers MUST treat that as
+    /// "unknown", never "zero free". (The quota path in particular fails *open* on
+    /// `None`: enforcing a 0-byte limit would lock every user out of uploading.)
+    /// Cached free-space reading for `path`.
+    ///
+    /// The cache is keyed BY PATH. It used to hold a single slot and ignore its argument on a hit,
+    /// so it would happily return the media volume's numbers for any other path within the TTL.
+    /// That was invisible only because every caller happened to pass `media_path` — the first
+    /// caller to ask about a different volume (e.g. the exports volume, which is a separate mount)
+    /// would have silently got the wrong filesystem's free space.
+    pub fn snapshot(&self, path: &Path) -> Option<DiskInfo> {
+        if let Some((cached_path, info, at)) = self.inner.read().unwrap().as_ref()
+            && cached_path == path
+            && at.elapsed() < TTL
+        {
+            return Some(*info);
+        }
+        let info = read_disk_for_path(path)?;
+        *self.inner.write().unwrap() = Some((path.to_path_buf(), info, Instant::now()));
+        Some(info)
+    }
+}
+
+impl Default for DiskCache {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+/// UNCACHED free-space reading for the filesystem backing `path`.
+///
+/// Deliberately bypasses [`DiskCache`]. The cache exists for the quota poll, where a 15s-stale
+/// number is fine because it is only ever advisory. The export preflight is the opposite case: it
+/// decides whether to start writing a multi-GB archive, and the sibling export worker running
+/// concurrently can move free space by tens of gigabytes well inside the TTL. A stale reading there
+/// would authorise exactly the write that fills the disk.
+pub fn free_bytes(path: &Path) -> Option<u64> {
+    read_disk_for_path(path).map(|d| d.free)
+}
+
+/// Resolve the filesystem backing `media_path` and read its total/free bytes.
+///
+/// Snapshots the mount table via `sysinfo`, then delegates the selection to the pure
+/// [`select_disk`] so the (fiddly, edge-case-prone) matching logic is unit-testable
+/// without touching the real filesystem.
+fn read_disk_for_path(media_path: &Path) -> Option<DiskInfo> {
+    let disks = sysinfo::Disks::new_with_refreshed_list();
+    let mounts: Vec<(String, u64, u64)> = disks
+        .iter()
+        .map(|d| {
+            (
+                d.mount_point().to_string_lossy().to_string(),
+                d.total_space(),
+                d.available_space(),
+            )
+        })
+        .collect();
+    select_disk(&mounts, &media_path.to_string_lossy())
+}
+
+/// Pick the filesystem for `media_path` from a `(mount_point, total, free)` table.
+///
+/// Chooses the **longest** mount point that is a prefix of `media_path` (the most
+/// specific filesystem) rather than the first match — otherwise the root `/` mount,
+/// which prefixes every absolute path, could shadow a dedicated `/media` volume. Falls
+/// back to `/` when nothing prefixes the path (e.g. a relative media path), and to
+/// `None` when even that is absent — the caller treats `None` as "unknown" and fails
+/// open on quota.
+fn select_disk(mounts: &[(String, u64, u64)], media_path: &str) -> Option<DiskInfo> {
+    mounts
+        .iter()
+        .filter(|(mp, _, _)| media_path.starts_with(mp.as_str()))
+        .max_by_key(|(mp, _, _)| mp.len())
+        .or_else(|| mounts.iter().find(|(mp, _, _)| mp == "/"))
+        .map(|(_, total, free)| DiskInfo {
+            total: *total,
+            free: *free,
+        })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::select_disk;
+
+    #[test]
+    fn picks_longest_matching_mount() {
+        // Both "/" and "/media" prefix the path; the dedicated volume must win.
+        let mounts = vec![("/".to_string(), 100, 40), ("/media".to_string(), 200, 150)];
+        let d = select_disk(&mounts, "/media/originals/x.jpg").unwrap();
+        assert_eq!((d.total, d.free), (200, 150));
+    }
+
+    #[test]
+    fn falls_back_to_root_when_no_specific_mount_matches() {
+        let mounts = vec![("/".to_string(), 100, 40), ("/media".to_string(), 200, 150)];
+        // "/var/lib" is only prefixed by "/".
+        let d = select_disk(&mounts, "/var/lib/data").unwrap();
+        assert_eq!((d.total, d.free), (100, 40));
+    }
+
+    #[test]
+    fn relative_path_uses_root_fallback() {
+        let mounts = vec![("/".to_string(), 100, 40)];
+        // A relative path prefixes nothing, so the explicit "/" fallback applies.
+        let d = select_disk(&mounts, "media/originals").unwrap();
+        assert_eq!((d.total, d.free), (100, 40));
+    }
+
+    #[test]
+    fn none_when_no_mount_matches_and_no_root() {
+        // No "/" present and nothing prefixes the relative path → unknown (fail-open).
+        let mounts = vec![("/data".to_string(), 100, 40)];
+        assert!(select_disk(&mounts, "relative/path").is_none());
+    }
+
+    #[test]
+    fn none_on_empty_mount_table() {
+        assert!(select_disk(&[], "/media/x").is_none());
+    }
+}

backend/src/services/imaging.rs

@@ -0,0 +1,297 @@
+//! Shared image decoding.
+//!
+//! Exists so there is exactly ONE way to turn a file on disk into a `DynamicImage` in this
+//! codebase. Two properties have to hold everywhere an image is decoded, and both were
+//! previously re-derived per call site — which is how they drifted apart:
+//!
+//! - **EXIF orientation must be applied.** Phones do not rotate sensor data; they record how
+//!   the camera was held in a tag and store the pixels as shot. `image::open` and
+//!   `ImageReader::decode` both hand back the raw pixels and ignore that tag, and re-encoding
+//!   to JPEG writes no EXIF, so the derivative is permanently sideways while the untouched
+//!   original still renders upright. The compression worker was fixed; the export worker was
+//!   not, so every portrait photo came out sideways in the keepsake's HTML viewer.
+//! - **Decode limits must be set.** The upload body cap bounds the file on disk, but a small
+//!   file can decode to enormous dimensions (a ~1 MB image expanding to 50k×50k px), OOM-ing
+//!   the box. `image::open` applies NO limits at all, so the export path was also decoding
+//!   arbitrary user-supplied images unbounded.
+
+use anyhow::{Context, Result};
+use image::{DynamicImage, ImageDecoder};
+use std::path::Path;
+
+/// Bounds for any decode of user-supplied image data. The per-axis cap covers any real phone
+/// photo; `max_alloc` bounds the decoded buffer — but only because `decode_oriented` reserves
+/// against it explicitly, see there.
+///
+/// Sized against the deployment: the app container is capped at 1 GiB and the compression
+/// worker runs `compression_concurrency` decodes at once (default 2), so 256 MiB per decode
+/// leaves headroom for the resize buffers and the runtime.
+fn decode_limits() -> image::Limits {
+    let mut limits = image::Limits::default();
+    limits.max_image_width = Some(12_000);
+    limits.max_image_height = Some(12_000);
+    limits.max_alloc = Some(256 * 1024 * 1024);
+    limits
+}
+
+/// True when re-running the exact same work on the exact same bytes cannot possibly
+/// succeed, so retrying only burns wall-clock and log noise.
+///
+/// Deliberately narrow. Only the `ImageError` variants that are a property of the *input*
+/// count: the file will not shrink, gain codec support, or un-corrupt itself between
+/// attempts. `IoError` is excluded on purpose — an ENOSPC while writing a derivative, or
+/// EMFILE under load, is exactly the transient case the retry exists for.
+pub fn is_permanent_image_error(err: &anyhow::Error) -> bool {
+    err.chain().any(|cause| {
+        matches!(
+            cause.downcast_ref::<image::ImageError>(),
+            Some(
+                image::ImageError::Limits(_)
+                    | image::ImageError::Unsupported(_)
+                    | image::ImageError::Decoding(_)
+            )
+        )
+    })
+}
+
+/// Build a decoder for `path` with the budget enforced, WITHOUT reading any pixels.
+///
+/// Single source of truth for "may this image be decoded at all": both the upload
+/// admission check and the compression worker go through here, so they cannot disagree
+/// about what is acceptable.
+fn decoder_within_budget(path: &Path) -> Result<impl image::ImageDecoder> {
+    let mut reader = image::ImageReader::open(path)
+        .context("failed to open image")?
+        .with_guessed_format()
+        .context("failed to read image header")?;
+    let mut limits = decode_limits();
+    reader.limits(limits.clone());
+
+    // We need `into_decoder` rather than `decode()` to read the EXIF orientation tag before
+    // the pixels are consumed. But the two are NOT equivalent on safety: `decode()` performs
+    //
+    //     limits.reserve(decoder.total_bytes())?;
+    //
+    // between building the decoder and reading the image, and `into_decoder()` skips it (the
+    // crate's own FIXME concedes `from_decoder` doesn't compensate). Nothing else enforces
+    // `max_alloc` — the JPEG decoder's `set_limits` only checks support and dimensions — so
+    // without the line below the budget is inert and the ONLY bound is the per-axis cap. That
+    // leaves 12000x12000 decodable at 412 MiB, and two concurrent at 824 MiB against a 1 GiB
+    // container. Re-add it, exactly as `decode()` does.
+    let mut decoder = reader.into_decoder().context("failed to decode image")?;
+    limits
+        .reserve(decoder.total_bytes())
+        .context("image too large to decode within the memory budget")?;
+    decoder
+        .set_limits(limits)
+        .context("image too large to decode within the memory budget")?;
+    Ok(decoder)
+}
+
+/// Rough peak heap an image will cost to turn into derivatives, read from the HEADER only —
+/// no pixels are decoded. `None` when the header can't be read or the image is over budget
+/// (the caller is about to fail on it anyway).
+///
+/// Two terms, and the second is the one that surprises:
+///
+/// - the decoded buffer, `width * height * channels`; and
+/// - the resize intermediate. `image`'s Lanczos3 path accumulates in `f32`, so the buffer
+///   between the horizontal and vertical passes is `new_width * old_height * 4 channels * 4
+///   bytes` — 16 bytes per pixel-row-slot, not the 4 the output uses. For an 8000x8000
+///   original that is 262 MiB on top of a 244 MiB decode, measured. It is bigger than the
+///   decode for any tall image, which is why "the decode is bounded by max_alloc" was never
+///   the whole story.
+///
+/// Used to decide whether an image is heavy enough to need exclusive use of the box's memory
+/// headroom, NOT to reject anything.
+pub fn estimated_processing_peak_bytes(path: &Path, display_edge: u32) -> Option<u64> {
+    let decoder = decoder_within_budget(path).ok()?;
+    let (width, height) = decoder.dimensions();
+    let decoded = decoder.total_bytes();
+
+    // Aspect-preserving fit into `display_edge`, matching DynamicImage::resize. No downscale
+    // means no intermediate at all.
+    let intermediate = if width > display_edge || height > display_edge {
+        let ratio = f64::from(display_edge) / f64::from(width.max(height));
+        let new_width = (f64::from(width) * ratio).round().max(1.0) as u64;
+        new_width * u64::from(height) * 16
+    } else {
+        0
+    };
+
+    Some(decoded.saturating_add(intermediate))
+}
+
+/// Megapixels an image would decode to, or `None` if its header can't be read. Used only
+/// to put a concrete number in the message the guest sees.
+pub fn megapixels(path: &Path) -> Option<f64> {
+    let reader = image::ImageReader::open(path)
+        .ok()?
+        .with_guessed_format()
+        .ok()?;
+    let (w, h) = reader.into_dimensions().ok()?;
+    Some(f64::from(w) * f64::from(h) / 1_000_000.0)
+}
+
+/// True when an image cannot be decoded specifically because it would exceed the memory
+/// budget — read from the header, no pixels touched.
+///
+/// Called at upload admission so a guest who sends a 100 MP photo is told at the door, with
+/// a reason they can act on, instead of the upload being accepted with a 201 and then
+/// silently soft-deleted minutes later when the worker gives up on it.
+///
+/// Deliberately narrow: ONLY the budget. A corrupt, truncated or unsupported file also
+/// fails to build a decoder, but rejecting those here would change a contract the
+/// adversarial suite pins on purpose — acceptance follows the magic bytes, and a payload
+/// with a valid JPEG header is accepted regardless of what follows it. Those go to the
+/// compression worker as before, which handles them gracefully and (since the retry
+/// classifier) no longer burns backoff on them.
+pub fn exceeds_decode_budget(path: &Path) -> bool {
+    match decoder_within_budget(path) {
+        Ok(_) => false,
+        Err(e) => e.chain().any(|cause| {
+            matches!(
+                cause.downcast_ref::<image::ImageError>(),
+                Some(image::ImageError::Limits(_))
+            )
+        }),
+    }
+}
+
+/// Decode an image from disk with decompression-bomb limits applied and its EXIF
+/// orientation baked into the pixels.
+///
+/// Blocking — call inside `spawn_blocking`.
+pub fn decode_oriented(path: &Path) -> Result<DynamicImage> {
+    let mut decoder = decoder_within_budget(path)?;
+
+    // Cheap, and it happens BEFORE any pixels are read: an oversized image costs a header
+    // parse, not an allocation.
+    let orientation = decoder
+        .orientation()
+        .unwrap_or(image::metadata::Orientation::NoTransforms);
+    let mut img = DynamicImage::from_decoder(decoder).context("failed to decode image")?;
+    img.apply_orientation(orientation);
+    Ok(img)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// Shared with the e2e suite rather than duplicating 568 KiB of binary: the same file
+    /// drives `02-upload/oversized-image` so both layers assert on one artefact.
+    const HUGE: &str = concat!(
+        env!("CARGO_MANIFEST_DIR"),
+        "/../e2e/fixtures/media/huge-99mp.jpg"
+    );
+
+    #[test]
+    fn rejects_an_image_that_would_blow_the_allocation_budget() {
+        // 11000x9000 = 99 MP. Deliberately UNDER the 12000px per-axis cap, so the axis check
+        // cannot reject it — the allocation budget is the only thing that can, which is
+        // exactly what makes this a regression test rather than a restatement of the axis cap.
+        // 283 MiB decoded as RGB8 against a 256 MiB budget, from 568 KiB on disk.
+        //
+        // This failed before the guard was restored: `ImageReader::decode` performs
+        // `limits.reserve(decoder.total_bytes())`, and `into_decoder()` — which we need for
+        // the EXIF tag — skips it, so `max_alloc` was inert and this decoded happily.
+        // Map the Ok arm to its dimensions first: on failure `expect_err` Debug-prints the
+        // value, and Debug on a DynamicImage dumps every pixel — 283 MiB of output.
+        let err = decode_oriented(Path::new(HUGE))
+            .map(|img| (img.width(), img.height()))
+            .expect_err("a 99 MP image must be refused, not allocated");
+        let msg = format!("{err:#}");
+        assert!(
+            msg.to_lowercase().contains("limit") || msg.to_lowercase().contains("memory"),
+            "expected a limits error, got: {msg}"
+        );
+    }
+
+    #[test]
+    fn an_oversized_image_is_a_permanent_failure() {
+        // The retry loop must not burn 2s + 4s of backoff on this: the file will not shrink
+        // between attempts, so all three attempts reach the identical conclusion.
+        let err = decode_oriented(Path::new(HUGE))
+            .map(|img| (img.width(), img.height()))
+            .expect_err("fixture must exceed the budget");
+        assert!(
+            is_permanent_image_error(&err),
+            "a Limits error can never succeed on retry: {err:#}"
+        );
+    }
+
+    #[test]
+    fn a_plain_io_error_is_not_permanent() {
+        // The mirror that keeps the classifier honest. ENOSPC while writing a derivative, or
+        // EMFILE under load, is exactly what the retry exists for — misclassifying those as
+        // permanent would turn a transient blip back into the data loss round 1 fixed.
+        let err = decode_oriented(Path::new("/nonexistent/definitely-not-here.jpg"))
+            .map(|img| (img.width(), img.height()))
+            .expect_err("a missing file must error");
+        assert!(
+            !is_permanent_image_error(&err),
+            "an IO error must stay retryable: {err:#}"
+        );
+    }
+
+    #[test]
+    fn admission_rejects_only_the_over_budget_case() {
+        // Admission and processing must agree about SIZE — a photo accepted at the door and
+        // then rejected by the worker for being too big is the failure this pair prevents.
+        assert!(
+            exceeds_decode_budget(Path::new(HUGE)),
+            "admission must reject what the decoder rejects for size"
+        );
+        let ordinary = concat!(
+            env!("CARGO_MANIFEST_DIR"),
+            "/../e2e/fixtures/media/portrait-exif6.jpg"
+        );
+        assert!(
+            !exceeds_decode_budget(Path::new(ordinary)),
+            "admission must accept an ordinary photo"
+        );
+    }
+
+    #[test]
+    fn admission_does_not_reject_a_merely_undecodable_file() {
+        // The narrowing that keeps the adversarial contract intact: a payload with valid
+        // JPEG magic bytes and nothing behind them cannot be decoded, but acceptance follows
+        // the magic bytes by design (07-adversarial/file-upload-attacks). It is the worker's
+        // job to fail it, not admission's — admission is only the resource guard.
+        let dir = std::env::temp_dir().join("eventsnap-imaging-test");
+        std::fs::create_dir_all(&dir).expect("tmp dir");
+        let stub = dir.join("magic-only.jpg");
+        let mut bytes = vec![0u8; 1024];
+        bytes[..3].copy_from_slice(&[0xFF, 0xD8, 0xFF]);
+        std::fs::write(&stub, &bytes).expect("write stub");
+
+        assert!(
+            !exceeds_decode_budget(&stub),
+            "a corrupt file is not an over-budget file"
+        );
+        assert!(
+            decode_oriented(&stub)
+                .map(|i| (i.width(), i.height()))
+                .is_err(),
+            "...but it must still fail in the worker"
+        );
+        let _ = std::fs::remove_file(&stub);
+    }
+
+    #[test]
+    fn still_decodes_an_ordinary_photo_and_applies_orientation() {
+        // The guard must not have become a blanket refusal. This fixture is 40x20 stored with
+        // EXIF Orientation=6, so a correct decode returns it rotated to 20x40 portrait.
+        let path = concat!(
+            env!("CARGO_MANIFEST_DIR"),
+            "/../e2e/fixtures/media/portrait-exif6.jpg"
+        );
+        let img = decode_oriented(Path::new(path)).expect("an ordinary photo must decode");
+        assert_eq!(
+            (img.width(), img.height()),
+            (20, 40),
+            "EXIF orientation must still be applied after restoring the guard"
+        );
+    }
+}

backend/src/services/jobs.rs

@@ -1,73 +0,0 @@
-//! Shared shape for long-running background work.
-//!
-//! Today's [`compression`](crate::services::compression) and [`export`](crate::services::export)
-//! pipelines each implement their own progress + SSE plumbing. They could converge on the
-//! trait sketched here so future jobs (analytics, archival, ...) plug into one progress
-//! pipeline.
-//!
-//! This module is intentionally a *sketch*: the existing services are not yet wired to
-//! it. The aim is to (a) document the convention so new jobs follow it, (b) make the
-//! refactor mechanical when someone is ready to do it. See `docs/IDEAS.md` —
-//! "Maintainability principles" — for the rationale.
-//!
-//! Example of an eventual implementor:
-//!
-//! ```ignore
-//! struct ZipExport { event_id: Uuid, /* … */ }
-//!
-//! impl BackgroundJob for ZipExport {
-//!     fn name(&self) -> &'static str { "zip-export" }
-//!     async fn run(self, ctx: JobContext) -> Result<()> {
-//!         for (i, item) in items.iter().enumerate() {
-//!             ctx.report(percent(i, items.len())).await?;
-//!             // … write to zip …
-//!         }
-//!         Ok(())
-//!     }
-//! }
-//! ```
-
-use anyhow::Result;
-
-/// Handle handed to a running job: reports progress and emits SSE events.
-///
-/// Wraps the existing SSE broadcaster and an optional `export_job` row. Implementors
-/// don't need to know about `state.sse_tx` directly — they call [`JobContext::report`]
-/// and get the same effect.
-pub struct JobContext {
-    pub job_id: Option<uuid::Uuid>,
-    pub event_kind: &'static str,
-    pub sse_tx: tokio::sync::broadcast::Sender<crate::state::SseEvent>,
-    pub pool: sqlx::PgPool,
-}
-
-impl JobContext {
-    /// Update progress (0..=100) and broadcast an SSE tick. Cheap to call often —
-    /// rate-limit at the call site if a job emits at > 10 Hz.
-    pub async fn report(&self, percent: u8) -> Result<()> {
-        if let Some(job_id) = self.job_id {
-            sqlx::query("UPDATE export_job SET progress_pct = $1 WHERE id = $2")
-                .bind(percent as i16)
-                .bind(job_id)
-                .execute(&self.pool)
-                .await?;
-        }
-        let _ = self.sse_tx.send(crate::state::SseEvent::new(
-            self.event_kind,
-            serde_json::json!({ "progress_pct": percent }).to_string(),
-        ));
-        Ok(())
-    }
-}
-
-/// One unit of work that publishes progress through a [`JobContext`].
-///
-/// `run` consumes `self`; spawn with `tokio::spawn` at the caller. Errors propagate;
-/// the caller is responsible for mapping them to `export_job.error_message` or
-/// equivalent. Implementors stay small — the trait deliberately has no `cancel`
-/// or `pause`; we have not needed those yet.
-#[allow(async_fn_in_trait)]
-pub trait BackgroundJob: Send + 'static {
-    fn name(&self) -> &'static str;
-    async fn run(self, ctx: JobContext) -> Result<()>;
-}

backend/src/services/maintenance.rs

@@ -9,10 +9,13 @@
 //!    users staring at a spinner. Resetting them on startup recovers gracefully.
 //!
 //! 2. **Periodic tasks** — pruning that should happen "every hour" rather than per
-//!    request: expired sessions (otherwise the table grows unboundedly), and the
+//!    request: expired sessions (otherwise the table grows unboundedly), the
 //!    rate-limiter's in-memory windows (so keys for IPs that left long ago don't
-//!    accumulate).
+//!    accumulate), and the media of soft-deleted uploads — both the ones whose compression
+//!    permanently failed and the ones a guest or host deliberately removed — which are
+//!    retained for a recovery window and then reclaimed.
 
+use std::path::PathBuf;
 use std::time::Duration;
 
 use sqlx::PgPool;
@@ -20,6 +23,42 @@ use sqlx::PgPool;
 use crate::services::rate_limiter::RateLimiter;
 use crate::services::sse_tickets::SseTicketStore;
 
+/// How long a permanently-failed upload's original is kept on disk before it is
+/// reclaimed.
+///
+/// The compression worker stops deleting originals on failure — a transient error must
+/// never destroy the guest's only copy of a photo they can't retake. But the row is
+/// soft-deleted and the uploader's quota IS refunded, so without a sweep those bytes are
+/// invisible, unowned, and free: a reproducible codec failure lets one guest accumulate
+/// orphans at no personal cost, and because `active_uploaders` counts only users with
+/// non-deleted uploads, dropping out of that count actually RAISES everyone's per-user
+/// ceiling while the disk gets fuller.
+///
+/// Two weeks is comfortably longer than any single event, so an operator investigating a
+/// failed upload still has the file, while the leak stays bounded.
+const FAILED_ORIGINAL_RETENTION_DAYS: i64 = 14;
+
+/// How long a DELIBERATELY deleted upload's files are kept before they are reclaimed.
+///
+/// The same leak, reached by the ordinary path rather than the exceptional one.
+/// `soft_delete_in_event` stamps `deleted_at` and refunds `total_upload_bytes`, but nothing ever
+/// removed the bytes — so the quota stopped bounding the disk. Upload 500 MB, delete, quota is back
+/// to zero, upload another 500 MB: not an attack, just a guest curating their camera roll, which is
+/// what people do. The host then sees guests hitting "Du hast dein Upload-Limit erreicht" while the
+/// admin widget shows a disk full of files no upload row points at, and the quota message is
+/// actively misleading because the space really is gone — just not to anyone the accounting can
+/// name.
+///
+/// Much shorter than the failure window on purpose. Fourteen days outlives the whole event, so a
+/// deliberate delete would never reclaim anything while it mattered. A day still gives an operator
+/// a recovery window for a mis-tap.
+///
+/// NOTE what this does NOT do: within the window the bytes are still spent and still unaccounted,
+/// so a guest deleting and re-uploading through an eight-hour event can outrun the sweep. Bounding
+/// that would mean holding the quota until the file is actually reclaimed rather than refunding at
+/// `deleted_at` — a deliberate trade, and the reason the low-disk warning exists.
+const DELETED_UPLOAD_RETENTION_HOURS: i64 = 24;
+
 /// Reset rows left in flight by a previous crashed instance. Run once on startup,
 /// before the HTTP server starts taking requests, so users never observe the
 /// half-state.
@@ -44,8 +83,23 @@ pub async fn startup_recovery(pool: &PgPool) {
         Err(e) => tracing::error!("startup recovery: failed to sweep uploads: {e:#}"),
     }
 
-    // Export jobs interrupted mid-run. Mark 'failed' so the host can re-trigger.
-    // The `UNIQUE(event_id, type)` constraint would otherwise block re-release.
+    // Export jobs interrupted mid-run are marked 'failed' here so they aren't left
+    // 'running' forever. The host CANNOT re-trigger a released export (release_gallery
+    // rejects an already-released event), so `export::recover_exports` re-spawns these
+    // failed-but-released jobs from `main` once `AppState` exists (it needs the media
+    // paths + SSE sender this fn doesn't have).
+    //
+    // SINGLE-INSTANCE ASSUMPTION: this sweep is unscoped — it reaps every `running` row, not just
+    // this process's. That is correct for the supported deployment (one app container; see
+    // docker-compose.yml), where no other process can own a job at boot. If EventSnap is ever run
+    // with more than one replica, a booting replica would mark a peer's live workers `failed`.
+    // This is NOT merely wasteful — do not assume the epoch model contains it. Recovery re-arms the
+    // job at the SAME epoch, so the reaped-but-still-alive worker and the fresh one would BOTH hold
+    // that epoch; the guards carry no owner/lease token, so they share the same artifact paths and
+    // either can win the other's `finalize_job`. That can corrupt or delete the keepsake. Running
+    // more than one replica therefore requires an owner/lease/heartbeat on export_job first. That
+    // machinery is not worth building for a single-container app — so this is a documented
+    // CONSTRAINT, not a hidden assumption: do not scale this service horizontally as-is.
     match sqlx::query(
         "UPDATE export_job
          SET status = 'failed',
@@ -66,6 +120,19 @@ pub async fn startup_recovery(pool: &PgPool) {
     }
 }
 
+/// How long a file in `originals/` may exist without a database row before it is treated as
+/// abandoned.
+///
+/// This window is the ONLY thing making the sweep safe, because the upload handler renames the
+/// temp file into its final path BEFORE committing the row: for a short moment a perfectly
+/// healthy upload legitimately looks exactly like an orphan. Six hours is far beyond any live
+/// request (a 576 MiB body over a bad venue uplink is minutes, and the request itself is bounded
+/// by the reverse proxy) while still reclaiming the leak inside a single event.
+///
+/// DO NOT SHORTEN THIS to make a test faster — a value below the longest possible in-flight
+/// upload deletes photos out from under the request that is committing them.
+const ORPHAN_UPLOAD_RETENTION_HOURS: u64 = 6;
+
 /// Spawns a background task that periodically:
 /// - deletes session rows whose `expires_at` is more than a day in the past
 /// - prunes the in-memory rate-limiter HashMap of empty windows
@@ -76,6 +143,7 @@ pub fn spawn_periodic_tasks(
     pool: PgPool,
     rate_limiter: RateLimiter,
     sse_tickets: SseTicketStore,
+    media_path: PathBuf,
 ) {
     tokio::spawn(async move {
         let mut tick = tokio::time::interval(Duration::from_secs(3600));
@@ -84,12 +152,118 @@ pub fn spawn_periodic_tasks(
         loop {
             tick.tick().await;
             cleanup_sessions(&pool).await;
+            cleanup_deleted_media(&pool, &media_path).await;
+            sweep_orphan_originals(&pool, &media_path).await;
             rate_limiter.prune();
             sse_tickets.prune();
         }
     });
 }
 
+/// Reclaim the media of soft-deleted uploads once they are past their retention window.
+///
+/// ONLY ever touches rows with `deleted_at IS NOT NULL`, so it can never reach a live upload. Two
+/// classes, two windows, because the two deletes mean different things:
+///
+/// - a compression failure the guest didn't ask for and may want investigated —
+///   [`FAILED_ORIGINAL_RETENTION_DAYS`];
+/// - a deliberate removal by the guest or the host — [`DELETED_UPLOAD_RETENTION_HOURS`].
+///
+/// ALL FOUR paths are reclaimed, not just the original. The previous version cleared
+/// `original_path` alone, which was right for its only case (a failed compression produces no
+/// derivatives) but wrong the moment the sweep reaches a successfully processed upload: preview,
+/// display and thumbnail are each a separate file on disk, none of them counted in
+/// `original_size_bytes`, and nothing else ever removed them.
+///
+/// Every column is cleared in the same pass, which makes the sweep idempotent and stops a later run
+/// re-reporting files that are already gone. The ROW is kept: it is the audit trail, it costs a few
+/// hundred bytes, and `backfill_stale_derivatives` is guarded on `deleted_at IS NULL` so a nulled
+/// `preview_path` can never make it regenerate what was just reclaimed.
+async fn cleanup_deleted_media(pool: &PgPool, media_path: &std::path::Path) {
+    type Row = (
+        uuid::Uuid,
+        String,
+        Option<String>,
+        Option<String>,
+        Option<String>,
+    );
+    let rows = sqlx::query_as::<_, Row>(
+        "SELECT id, original_path, preview_path, display_path, thumbnail_path FROM upload
+         WHERE deleted_at IS NOT NULL
+           AND CASE WHEN compression_status = 'failed'
+                    THEN deleted_at < NOW() - ($1 || ' days')::interval
+                    ELSE deleted_at < NOW() - ($2 || ' hours')::interval
+               END
+           AND (original_path <> '' OR preview_path IS NOT NULL
+                OR display_path IS NOT NULL OR thumbnail_path IS NOT NULL)",
+    )
+    .bind(FAILED_ORIGINAL_RETENTION_DAYS.to_string())
+    .bind(DELETED_UPLOAD_RETENTION_HOURS.to_string())
+    .fetch_all(pool)
+    .await;
+
+    let rows = match rows {
+        Ok(r) => r,
+        Err(e) => {
+            tracing::warn!(error = ?e, "deleted-media sweep query failed");
+            return;
+        }
+    };
+    if rows.is_empty() {
+        return;
+    }
+
+    let mut reclaimed = 0usize;
+    for (id, original, preview, display, thumbnail) in rows {
+        let paths: Vec<String> = std::iter::once(original)
+            .filter(|p| !p.is_empty())
+            .chain([preview, display, thumbnail].into_iter().flatten())
+            .collect();
+
+        // All-or-nothing per row: the columns are only cleared once every file for that upload is
+        // gone. Clearing after a partial success would strand the survivors with nothing pointing
+        // at them — the same unowned-bytes state this sweep exists to drain.
+        let mut all_gone = true;
+        for rel in &paths {
+            let absolute = media_path.join(rel);
+            match tokio::fs::remove_file(&absolute).await {
+                Ok(()) => reclaimed += 1,
+                // Already gone (manual cleanup, restored backup) — still counts as reclaimed for
+                // the purpose of clearing the columns, or the row is re-selected every hour forever.
+                Err(e) if e.kind() == std::io::ErrorKind::NotFound => {}
+                Err(e) => {
+                    tracing::warn!(error = ?e, %id, path = %absolute.display(),
+                        "could not reclaim deleted media; leaving the row for the next sweep");
+                    all_gone = false;
+                }
+            }
+        }
+        if !all_gone {
+            continue;
+        }
+
+        if let Err(e) = sqlx::query(
+            "UPDATE upload SET original_path = '', preview_path = NULL,
+                    display_path = NULL, thumbnail_path = NULL
+             WHERE id = $1",
+        )
+        .bind(id)
+        .execute(pool)
+        .await
+        {
+            tracing::warn!(error = ?e, %id, "reclaimed the files but could not clear the paths");
+        }
+    }
+
+    if reclaimed > 0 {
+        tracing::info!(
+            "reclaimed {reclaimed} file(s) from soft-deleted uploads (deliberate deletes after \
+             {DELETED_UPLOAD_RETENTION_HOURS}h, compression failures after \
+             {FAILED_ORIGINAL_RETENTION_DAYS}d)"
+        );
+    }
+}
+
 async fn cleanup_sessions(pool: &PgPool) {
     match sqlx::query("DELETE FROM session WHERE expires_at < NOW() - INTERVAL '1 day'")
         .execute(pool)
@@ -102,3 +276,123 @@ async fn cleanup_sessions(pool: &PgPool) {
         Err(e) => tracing::warn!("session cleanup failed: {e:#}"),
     }
 }
+
+/// Reclaim files in `originals/` that no upload row references.
+///
+/// The backstop behind [`TempFileGuard`](crate::handlers::upload). The guard covers the
+/// process that is running; this covers the process that was killed — a SIGKILL, an OOM, or a
+/// power cut leaves whatever bytes had been written with no `Drop` to reclaim them, and those
+/// files are then permanently invisible: they have no row, so `cleanup_deleted_media` (which is
+/// row-driven) can never see them, and they are not counted against any quota while still
+/// consuming the free disk that `compute_storage_quota` divides among guests. On a single box
+/// where all three volumes share a filesystem, that ends with Postgres unable to write WAL.
+///
+/// Two classes:
+/// - `*.tmp` — an upload that never got as far as being renamed. Always safe past the window.
+/// - everything else — a final-named original whose commit never happened.
+async fn sweep_orphan_originals(pool: &PgPool, media_path: &std::path::Path) {
+    let originals = media_path.join("originals");
+    let cutoff = Duration::from_secs(ORPHAN_UPLOAD_RETENTION_HOURS * 3600);
+
+    // originals/{event_slug}/{uuid}.{ext} — one level of per-event directories.
+    let mut event_dirs = match tokio::fs::read_dir(&originals).await {
+        Ok(rd) => rd,
+        // Nothing uploaded yet; the directory is created lazily by the upload handler.
+        Err(_) => return,
+    };
+
+    let mut candidates: Vec<(String, std::path::PathBuf)> = Vec::new();
+    let mut temps_removed = 0u32;
+
+    while let Ok(Some(event_dir)) = event_dirs.next_entry().await {
+        if !event_dir
+            .file_type()
+            .await
+            .map(|t| t.is_dir())
+            .unwrap_or(false)
+        {
+            continue;
+        }
+        let slug = event_dir.file_name().to_string_lossy().to_string();
+        let Ok(mut files) = tokio::fs::read_dir(event_dir.path()).await else {
+            continue;
+        };
+        while let Ok(Some(entry)) = files.next_entry().await {
+            let Ok(meta) = entry.metadata().await else {
+                continue;
+            };
+            if !meta.is_file() {
+                continue;
+            }
+            // Too young to judge: an upload committing RIGHT NOW is indistinguishable from an
+            // orphan, because the rename precedes the commit.
+            let recent = meta
+                .modified()
+                .ok()
+                .and_then(|m| m.elapsed().ok())
+                .is_none_or(|age| age < cutoff);
+            if recent {
+                continue;
+            }
+
+            let name = entry.file_name().to_string_lossy().to_string();
+            if name.ends_with(".tmp") {
+                // A `.tmp` never has a row by construction — no DB check needed.
+                if tokio::fs::remove_file(entry.path()).await.is_ok() {
+                    temps_removed += 1;
+                }
+                continue;
+            }
+            candidates.push((format!("originals/{slug}/{name}"), entry.path()));
+        }
+    }
+
+    if temps_removed > 0 {
+        tracing::warn!(
+            "reclaimed {temps_removed} abandoned upload temp file(s) older than \
+             {ORPHAN_UPLOAD_RETENTION_HOURS}h"
+        );
+    }
+    if candidates.is_empty() {
+        return;
+    }
+
+    // One query per batch, not one per file: a backlog of thousands of orphans must not turn
+    // into thousands of round trips on an hourly timer.
+    let mut orphans_removed = 0u32;
+    for chunk in candidates.chunks(500) {
+        let paths: Vec<String> = chunk.iter().map(|(rel, _)| rel.clone()).collect();
+        // NO `deleted_at IS NULL` FILTER HERE. A soft-deleted row still points at its file
+        // during its retention window, and reclaiming that file is `cleanup_deleted_media`'s
+        // job — filtering here would race the two sweeps and destroy the exact files the
+        // recovery window exists to preserve.
+        let unreferenced: Result<Vec<(String,)>, _> = sqlx::query_as(
+            "SELECT p FROM unnest($1::text[]) AS p
+              WHERE NOT EXISTS (SELECT 1 FROM upload u WHERE u.original_path = p)",
+        )
+        .bind(&paths)
+        .fetch_all(pool)
+        .await;
+        let unreferenced = match unreferenced {
+            Ok(rows) => rows,
+            Err(e) => {
+                tracing::warn!(error = ?e, "orphan-original sweep query failed");
+                return;
+            }
+        };
+        for (rel,) in unreferenced {
+            if let Some((_, abs)) = chunk.iter().find(|(r, _)| *r == rel)
+                && tokio::fs::remove_file(abs).await.is_ok()
+            {
+                orphans_removed += 1;
+            }
+        }
+    }
+
+    if orphans_removed > 0 {
+        tracing::warn!(
+            "reclaimed {orphans_removed} original(s) with no upload row, older than \
+             {ORPHAN_UPLOAD_RETENTION_HOURS}h"
+        );
+    }
+}

backend/src/services/mod.rs

@@ -1,7 +1,9 @@
 pub mod compression;
 pub mod config;
+pub mod disk;
 pub mod export;
-pub mod jobs;
+pub mod imaging;
 pub mod maintenance;
 pub mod rate_limiter;
 pub mod sse_tickets;
+pub mod video;

backend/src/services/rate_limiter.rs

@@ -17,14 +17,20 @@ impl RateLimiter {
         }
     }
 
-    /// Returns `true` if the request is allowed, `false` if rate-limited.
-    pub fn check(&self, key: impl Into<String>, max: usize, window: Duration) -> bool {
-        self.check_with_retry(key, max, window).is_ok()
-    }
-
     /// Returns `Ok(())` if allowed, `Err(retry_after_secs)` if rate-limited.
     /// `retry_after_secs` is how long until the oldest slot in the window expires.
-    pub fn check_with_retry(&self, key: impl Into<String>, max: usize, window: Duration) -> Result<(), u64> {
+    ///
+    /// This is deliberately the ONLY entry point. There used to be a `check()` wrapper
+    /// returning a plain bool, and 7 of the 8 call sites used it and then hard-coded
+    /// `None` for the response's `Retry-After` — so a throttled client was told to back
+    /// off but never for how long. Forcing every caller through the `Result` makes the
+    /// retry delay impossible to discard by accident.
+    pub fn check_with_retry(
+        &self,
+        key: impl Into<String>,
+        max: usize,
+        window: Duration,
+    ) -> Result<(), u64> {
         let now = Instant::now();
         let key = key.into();
         let mut map = self.windows.lock().unwrap();
@@ -79,6 +85,11 @@ impl RateLimiter {
 /// appends is the real client. A client can prepend arbitrary spoofed values to
 /// the left of XFF to dodge throttles — those are ignored here. This assumes
 /// exactly one trusted proxy (Caddy); revisit if that changes.
+///
+/// Pass the peer address as `fallback`, never a constant. Every caller used to pass
+/// the literal `"unknown"`, so any request that arrived without XFF — i.e. anything
+/// reaching the app directly rather than through Caddy — shared ONE bucket with every
+/// other such request, turning the limiter into a self-inflicted global throttle.
 pub fn client_ip(headers: &axum::http::HeaderMap, fallback: &str) -> String {
     headers
         .get("x-forwarded-for")
@@ -99,45 +110,159 @@ mod tests {
     #[test]
     fn allows_up_to_max_then_blocks() {
         let rl = RateLimiter::new();
-        assert!(rl.check("k", 3, MIN));
-        assert!(rl.check("k", 3, MIN));
-        assert!(rl.check("k", 3, MIN));
-        assert!(!rl.check("k", 3, MIN), "the 4th request must be blocked");
+        assert!(rl.check_with_retry("k", 3, MIN).is_ok());
+        assert!(rl.check_with_retry("k", 3, MIN).is_ok());
+        assert!(rl.check_with_retry("k", 3, MIN).is_ok());
+        assert!(
+            rl.check_with_retry("k", 3, MIN).is_err(),
+            "the 4th request must be blocked"
+        );
     }
 
     #[test]
     fn keys_are_independent() {
         let rl = RateLimiter::new();
-        assert!(rl.check("a", 1, MIN));
-        assert!(!rl.check("a", 1, MIN));
-        assert!(rl.check("b", 1, MIN), "a different key has its own window");
+        assert!(rl.check_with_retry("a", 1, MIN).is_ok());
+        assert!(rl.check_with_retry("a", 1, MIN).is_err());
+        assert!(
+            rl.check_with_retry("b", 1, MIN).is_ok(),
+            "a different key has its own window"
+        );
     }
 
     #[test]
     fn window_slides_and_allows_again_after_expiry() {
         let rl = RateLimiter::new();
         let w = Duration::from_millis(40);
-        assert!(rl.check("k", 1, w));
-        assert!(!rl.check("k", 1, w));
+        assert!(rl.check_with_retry("k", 1, w).is_ok());
+        assert!(rl.check_with_retry("k", 1, w).is_err());
         std::thread::sleep(Duration::from_millis(55));
-        assert!(rl.check("k", 1, w), "the slot should expire once the window passes");
+        assert!(
+            rl.check_with_retry("k", 1, w).is_ok(),
+            "the slot should expire once the window passes"
+        );
+    }
+
+    /// `retry_after` is not a "some number in range" — it is the time until the oldest slot
+    /// in the window frees up, and it is surfaced to clients as the backoff they sleep for
+    /// (see `upload-queue.ts`). Asserting only `(1..=60)` spans the entire reachable domain
+    /// of a 60s window, so a hardcoded `Err(1)` would satisfy it while telling every client
+    /// to hammer the server a second later. Pin the actual value.
+    #[test]
+    fn retry_after_is_the_remaining_window() {
+        let rl = RateLimiter::new();
+
+        // The slot was consumed just now, so essentially the whole window remains.
+        // `as_secs()` truncates the sub-second remainder, so a 30s window reports 29.
+        let w30 = Duration::from_secs(30);
+        assert!(rl.check_with_retry("a", 1, w30).is_ok());
+        let a = rl.check_with_retry("a", 1, w30).unwrap_err();
+        assert_eq!(a, 29, "retry_after must be the remaining window, got {a}");
+
+        // A different window must yield a different retry_after: no single constant can
+        // satisfy both this and the assertion above.
+        let w10 = Duration::from_secs(10);
+        assert!(rl.check_with_retry("b", 1, w10).is_ok());
+        let b = rl.check_with_retry("b", 1, w10).unwrap_err();
+        assert_eq!(b, 9, "retry_after must scale with the window, got {b}");
     }
 
     #[test]
-    fn retry_after_is_between_one_and_window() {
+    fn retry_after_counts_down_as_the_window_elapses() {
         let rl = RateLimiter::new();
-        assert!(rl.check_with_retry("k", 1, MIN).is_ok());
-        let retry = rl.check_with_retry("k", 1, MIN).unwrap_err();
-        assert!((1..=60).contains(&retry), "retry_after {retry} out of range");
+        let w = Duration::from_secs(30);
+        assert!(rl.check_with_retry("k", 1, w).is_ok());
+        let first = rl.check_with_retry("k", 1, w).unwrap_err();
+
+        std::thread::sleep(Duration::from_millis(1200));
+        let second = rl.check_with_retry("k", 1, w).unwrap_err();
+
+        // A client that waits 1.2s must be told to wait ~1.2s less — otherwise the advertised
+        // backoff is a constant, not a deadline.
+        let shaved = first - second;
+        assert!(
+            (1..=2).contains(&shaved),
+            "1.2s of waiting must shorten the advertised backoff by ~1s (got {first} then {second})"
+        );
+    }
+
+    #[test]
+    fn retry_after_floors_at_one_second() {
+        let rl = RateLimiter::new();
+        let w = Duration::from_millis(800);
+        assert!(rl.check_with_retry("k", 1, w).is_ok());
+        let retry = rl.check_with_retry("k", 1, w).unwrap_err();
+        // The sub-second remainder truncates to 0; clients must never be told "retry in 0s"
+        // (that's a busy-loop). The `.max(1)` floor is what prevents it.
+        assert_eq!(
+            retry, 1,
+            "a sub-second remainder must floor to 1, got {retry}"
+        );
     }
 
     #[test]
     fn clear_resets_every_window() {
         let rl = RateLimiter::new();
-        assert!(rl.check("k", 1, MIN));
-        assert!(!rl.check("k", 1, MIN));
+        assert!(rl.check_with_retry("k", 1, MIN).is_ok());
+        assert!(rl.check_with_retry("k", 1, MIN).is_err());
         rl.clear();
-        assert!(rl.check("k", 1, MIN), "clear() must free the window");
+        assert!(
+            rl.check_with_retry("k", 1, MIN).is_ok(),
+            "clear() must free the window"
+        );
+    }
+
+    /// `prune()` is a memory-leak guard: without it a long-lived process keeps one HashMap
+    /// entry per IP that ever connected. Nothing in the public API observes the map size, so
+    /// the only way to catch a no-op body (`fn prune(&self) {}`) is to look at the map — the
+    /// tests module can see the private field.
+    #[test]
+    fn prune_drops_keys_whose_windows_have_fully_expired() {
+        let rl = RateLimiter::new();
+
+        // A key whose only timestamp is older than the 24h ceiling. We can't sleep for a day,
+        // so backdate the Instant directly.
+        let ancient = Instant::now()
+            .checked_sub(Duration::from_secs(25 * 60 * 60))
+            .expect("backdating an Instant by 25h");
+        rl.windows
+            .lock()
+            .unwrap()
+            .insert("stale".to_string(), vec![ancient]);
+
+        // ...alongside a key that is still inside its window.
+        assert!(rl.check_with_retry("live", 5, MIN).is_ok());
+        assert_eq!(rl.windows.lock().unwrap().len(), 2);
+
+        rl.prune();
+
+        let map = rl.windows.lock().unwrap();
+        assert!(
+            !map.contains_key("stale"),
+            "prune() must drop keys whose timestamps have all expired"
+        );
+        assert!(
+            map.contains_key("live"),
+            "prune() must keep keys that still have live timestamps"
+        );
+        assert_eq!(map.len(), 1, "exactly one key should survive the prune");
+    }
+
+    #[test]
+    fn prune_does_not_reset_a_live_window() {
+        // The counterpart to the test above: pruning must reclaim memory, never quota. If
+        // prune() dropped live keys, every background sweep would hand attackers a fresh
+        // budget.
+        let rl = RateLimiter::new();
+        assert!(rl.check_with_retry("k", 1, MIN).is_ok());
+        assert!(rl.check_with_retry("k", 1, MIN).is_err());
+
+        rl.prune();
+
+        assert!(
+            rl.check_with_retry("k", 1, MIN).is_err(),
+            "prune() must not clear a window that is still active"
+        );
     }
 
     #[test]
@@ -152,7 +277,10 @@ mod tests {
     fn client_ip_ignores_spoofed_leftmost_entry() {
         // A client prepending a fake IP to dodge throttles must not win.
         let mut h = HeaderMap::new();
-        h.insert("x-forwarded-for", "1.2.3.4, 9.9.9.9, 203.0.113.7".parse().unwrap());
+        h.insert(
+            "x-forwarded-for",
+            "1.2.3.4, 9.9.9.9, 203.0.113.7".parse().unwrap(),
+        );
         assert_eq!(client_ip(&h, "fallback"), "203.0.113.7");
     }
 

backend/src/services/sse_tickets.rs

@@ -13,6 +13,16 @@ use rand::Rng;
 /// stream open. Tickets are consumed on use and expire after `TTL`.
 const TTL: Duration = Duration::from_secs(30);
 
+/// Ceiling on outstanding tickets across the whole process.
+///
+/// Not really about the bytes (~120 each) — about `issue` having had no bound of any kind.
+/// Sized well above a real event: ~1000 concurrent clients each holding one live 30 s ticket.
+const MAX_TICKETS: usize = 4096;
+
+/// Live tickets one session may hold. Above 1 because two tabs sharing a token open their
+/// EventSources concurrently; 4 absorbs that without letting a reconnect loop accumulate.
+const MAX_TICKETS_PER_SESSION: usize = 4;
+
 #[derive(Clone)]
 pub struct SseTicketStore {
     inner: Arc<Mutex<HashMap<String, Entry>>>,
@@ -31,10 +41,55 @@ impl SseTicketStore {
         }
     }
 
+    /// Drop every outstanding ticket. Used by the e2e TRUNCATE endpoint: tickets are bound to a
+    /// session token hash, and TRUNCATE deletes the sessions out from under them, so anything left
+    /// here is a dangling reference to a user that no longer exists.
+    pub fn clear(&self) {
+        self.inner.lock().unwrap().clear();
+    }
+
     /// Mint a new ticket bound to the caller's session (identified by token hash).
-    pub fn issue(&self, token_hash: String) -> String {
+    ///
+    /// `None` when the store is at capacity — the caller should answer 503, not evict.
+    ///
+    /// Three bounds, because `issue` had none: no size cap, no per-caller cap, and no rate
+    /// limit on the endpoint, while `prune` ran only hourly against a 30-second TTL. So any
+    /// authenticated session could loop the endpoint and grow the map for an hour.
+    pub fn issue(&self, token_hash: String) -> Option<String> {
         let ticket = random_ticket();
         let mut map = self.inner.lock().unwrap();
+
+        // Prune on issue rather than only hourly. This alone changes the bound from "tickets
+        // minted since the last maintenance tick" to "tickets live at once", which is what the
+        // 30 s TTL was always meant to express.
+        map.retain(|_, e| e.issued_at.elapsed() <= TTL);
+
+        // Cap the caller's own outstanding tickets, evicting their oldest. NOT one-per-session:
+        // two tabs sharing a token open their EventSources concurrently, and having tab B
+        // invalidate tab A's unconsumed ticket looks exactly like a flaky SSE connection.
+        let mut mine: Vec<(String, Instant)> = map
+            .iter()
+            .filter(|(_, e)| e.token_hash == token_hash)
+            .map(|(k, e)| (k.clone(), e.issued_at))
+            .collect();
+        if mine.len() >= MAX_TICKETS_PER_SESSION {
+            mine.sort_by_key(|(_, issued)| *issued);
+            for (key, _) in mine.iter().take(mine.len() - MAX_TICKETS_PER_SESSION + 1) {
+                map.remove(key);
+            }
+        }
+
+        // At capacity, REFUSE — never evict a stranger's ticket. Evicting would let one
+        // misbehaving client deny SSE to the whole venue, which is worse than failing the
+        // request that hit the ceiling.
+        if map.len() >= MAX_TICKETS {
+            tracing::warn!(
+                outstanding = map.len(),
+                "SSE ticket store at capacity; refusing to mint"
+            );
+            return None;
+        }
+
         map.insert(
             ticket.clone(),
             Entry {
@@ -42,7 +97,7 @@ impl SseTicketStore {
                 issued_at: Instant::now(),
             },
         );
-        ticket
+        Some(ticket)
     }
 
     /// Consume a ticket. Returns `Some(token_hash)` if the ticket exists and is
@@ -77,13 +132,23 @@ fn random_ticket() -> String {
 mod tests {
     use super::*;
 
+    /// `issue` now returns `Option`; in every test below the store is far from capacity, so an
+    /// `expect` here documents that refusing is exceptional rather than routine.
+    fn issue(store: &SseTicketStore, hash: &str) -> String {
+        store.issue(hash.into()).expect("store has capacity")
+    }
+
     #[test]
     fn issue_then_consume_returns_the_hash_exactly_once() {
         let store = SseTicketStore::new();
-        let ticket = store.issue("hash-1".into());
+        let ticket = issue(&store, "hash-1");
         assert_eq!(store.consume(&ticket).as_deref(), Some("hash-1"));
         // Single-use: a replay of the same ticket is rejected.
-        assert_eq!(store.consume(&ticket), None, "a consumed ticket must not be reusable");
+        assert_eq!(
+            store.consume(&ticket),
+            None,
+            "a consumed ticket must not be reusable"
+        );
     }
 
     #[test]
@@ -95,8 +160,8 @@ mod tests {
     #[test]
     fn issued_tickets_are_unique_and_hex() {
         let store = SseTicketStore::new();
-        let a = store.issue("h".into());
-        let b = store.issue("h".into());
+        let a = issue(&store, "h");
+        let b = issue(&store, "h");
         assert_ne!(a, b, "each ticket must be unique");
         assert_eq!(a.len(), 48, "24 random bytes → 48 hex chars");
         assert!(a.chars().all(|c| c.is_ascii_hexdigit()));
@@ -105,25 +170,104 @@ mod tests {
     #[test]
     fn fresh_ticket_survives_prune() {
         let store = SseTicketStore::new();
-        let ticket = store.issue("h".into());
+        let ticket = issue(&store, "h");
         store.prune(); // not expired → kept
         assert_eq!(store.consume(&ticket).as_deref(), Some("h"));
     }
 
-    #[test]
-    fn expired_ticket_consumes_to_none() {
-        // Construct an entry that is already past the TTL and confirm consume() rejects it.
-        let store = SseTicketStore::new();
-        let stale = "stale-ticket".to_string();
+    /// Build an entry that is already past the TTL.
+    fn insert_stale(store: &SseTicketStore, key: &str, token_hash: &str) {
         store.inner.lock().unwrap().insert(
-            stale.clone(),
+            key.to_string(),
             Entry {
-                token_hash: "h".into(),
+                token_hash: token_hash.into(),
                 issued_at: Instant::now()
                     .checked_sub(TTL + Duration::from_secs(1))
                     .expect("host uptime should exceed the ticket TTL"),
             },
         );
-        assert_eq!(store.consume(&stale), None, "an expired ticket must not authenticate");
+    }
+
+    #[test]
+    fn expired_ticket_consumes_to_none() {
+        let store = SseTicketStore::new();
+        insert_stale(&store, "stale-ticket", "h");
+        assert_eq!(
+            store.consume("stale-ticket"),
+            None,
+            "an expired ticket must not authenticate"
+        );
+    }
+
+    /// The TTL is 30 s but `prune` only ran hourly, so the map was really bounded by "tickets
+    /// minted in the last hour" — which is unbounded for a client in a loop.
+    #[test]
+    fn issuing_prunes_expired_entries() {
+        let store = SseTicketStore::new();
+        insert_stale(&store, "stale-a", "someone-else");
+        insert_stale(&store, "stale-b", "someone-else");
+        issue(&store, "h");
+        assert_eq!(
+            store.inner.lock().unwrap().len(),
+            1,
+            "issue must reclaim expired slots, not merely add to them"
+        );
+    }
+
+    /// Two tabs sharing a token is normal, so the per-session cap must be above 1 — but a
+    /// reconnect loop must not accumulate. The caller's OWN oldest is what gets evicted.
+    #[test]
+    fn a_session_is_capped_and_evicts_only_its_own_oldest() {
+        let store = SseTicketStore::new();
+        let stranger = issue(&store, "other-session");
+
+        let mut mine: Vec<String> = Vec::new();
+        for _ in 0..MAX_TICKETS_PER_SESSION + 2 {
+            mine.push(issue(&store, "mine"));
+        }
+
+        let live = mine
+            .iter()
+            .filter(|t| store.inner.lock().unwrap().contains_key(*t))
+            .count();
+        assert_eq!(live, MAX_TICKETS_PER_SESSION, "one session, bounded");
+        assert!(
+            store.inner.lock().unwrap().contains_key(&mine[mine.len() - 1]),
+            "the newest ticket is the one the caller is about to use"
+        );
+        assert_eq!(
+            store.consume(&stranger).as_deref(),
+            Some("other-session"),
+            "another session's ticket must survive — evicting it would let one client deny \
+             SSE to the venue"
+        );
+    }
+
+    /// At capacity the store REFUSES rather than evicting a stranger. Refusing fails the one
+    /// request that hit the ceiling; evicting would break an unrelated client's live stream.
+    #[test]
+    fn at_capacity_the_store_refuses_instead_of_evicting() {
+        let store = SseTicketStore::new();
+        {
+            let mut map = store.inner.lock().unwrap();
+            for i in 0..MAX_TICKETS {
+                map.insert(
+                    format!("filler-{i}"),
+                    Entry {
+                        token_hash: format!("session-{i}"),
+                        issued_at: Instant::now(),
+                    },
+                );
+            }
+        }
+        assert_eq!(
+            store.issue("newcomer".into()),
+            None,
+            "a full store must refuse, so the caller can answer 503"
+        );
+        assert!(
+            store.inner.lock().unwrap().contains_key("filler-0"),
+            "no existing ticket may be sacrificed to make room"
+        );
     }
 }

backend/src/services/video.rs

@@ -0,0 +1,233 @@
+//! Poster-frame extraction, shared by the compression worker and the HTML export.
+//!
+//! Both used to spawn `ffmpeg` themselves with the same broken invocation:
+//!
+//! ```text
+//! ffmpeg -i <src> -vframes 1 -ss 00:00:01 -vf scale=… -y <out>
+//! ```
+//!
+//! `-ss` AFTER `-i` is an output-side seek. Against a clip of a second or less ffmpeg exits **0 and
+//! writes nothing** — and both call sites gated on the exit status, so neither noticed. The worker
+//! then wrote `thumbnail_path` for a file that was never created (404 in the live feed) and the
+//! export listed the entry in `data.json` while the ZIP writer skipped it (a broken image tile in
+//! the keepsake). Every server-side signal stayed green. Phones produce such clips constantly:
+//! mis-taps, Live Photos, boomerangs.
+//!
+//! This module exists for the same reason `imaging.rs` does — that one was created when compression
+//! and export duplicated decode logic, and it paid off immediately when the `max_alloc` fix landed
+//! in both workers at once. Same duplication, same fix.
+
+use std::path::Path;
+use std::time::Duration;
+
+use anyhow::{Context, Result};
+
+/// A malformed video can hang `ffmpeg` indefinitely. In the compression worker that never releases
+/// the semaphore permit and the pool eventually deadlocks; in the export worker it strands the job
+/// at `running` so the keepsake never completes. `export.rs` had NO timeout at all before this
+/// module — sharing the spawn fixes that too.
+const FFMPEG_TIMEOUT: Duration = Duration::from_secs(120);
+
+/// Seek positions to try, in order.
+///
+/// One second first: the opening frame of a real video is often black, a fade-in, or motion-blurred
+/// as the camera settles, so it makes a poor poster. Zero second as the fallback, which is what
+/// makes short clips work — and it is genuinely required, not defensive. Moving `-ss` before `-i`
+/// (an input-side seek) is necessary but NOT sufficient: seeking to 1 s in a 1.000 s clip is still
+/// past the last frame, and ffmpeg still exits 0 having written nothing. Verified against the real
+/// production image.
+const SEEK_POSITIONS: &[&str] = &["00:00:01", "0"];
+
+/// Extract one poster frame from `src` into `dest`, scaled to `width` px wide.
+///
+/// `Ok(false)` means the video yielded no frame — a normal outcome for a very short or unusual
+/// clip, NOT an error. Callers must degrade (no poster) rather than fail the upload: treating this
+/// as an error would soft-delete every sub-second video, turning a cosmetic defect into data loss.
+///
+/// `Err` is reserved for something genuinely wrong — a hang we had to kill, or a failure to spawn.
+pub async fn extract_poster_frame(src: &Path, dest: &Path, width: u32) -> Result<bool> {
+    for seek in SEEK_POSITIONS {
+        // A stale file from a previous attempt would be indistinguishable from a fresh success.
+        let _ = tokio::fs::remove_file(dest).await;
+
+        run_ffmpeg(src, dest, width, seek).await?;
+
+        // THE CHECK BOTH CALL SITES WERE MISSING: ask the filesystem, not the exit status.
+        // Non-empty, because a zero-byte file is not a poster either.
+        if tokio::fs::metadata(dest)
+            .await
+            .map(|m| m.is_file() && m.len() > 0)
+            .unwrap_or(false)
+        {
+            return Ok(true);
+        }
+    }
+
+    // Leave nothing behind for a caller to mistake for a result.
+    let _ = tokio::fs::remove_file(dest).await;
+    Ok(false)
+}
+
+/// Run one ffmpeg attempt. A non-zero exit is NOT an error here — the artifact check above is the
+/// authority, and a corrupt input that fails at 1 s may still yield a frame at 0.
+async fn run_ffmpeg(src: &Path, dest: &Path, width: u32, seek: &str) -> Result<()> {
+    let child = tokio::process::Command::new("ffmpeg")
+        .args([
+            // BEFORE -i: an input-side seek. See SEEK_POSITIONS.
+            "-ss",
+            seek,
+            "-i",
+            src.to_str().unwrap_or_default(),
+            "-vframes",
+            "1",
+            "-vf",
+            &format!("scale={width}:-1"),
+            "-y",
+            dest.to_str().unwrap_or_default(),
+        ])
+        // ffmpeg writes the poster to `dest` itself; nothing here ever reads stdout, so
+        // giving it a pipe only created something that could fill.
+        .stdout(std::process::Stdio::null())
+        // stderr IS piped — it is the only diagnostic when a clip yields no frame — but it
+        // must be DRAINED, which is the whole point of `wait_with_output` below.
+        .stderr(std::process::Stdio::piped())
+        .kill_on_drop(true)
+        .spawn()
+        .context("failed to spawn ffmpeg")?;
+
+    // `wait_with_output`, NOT `wait`. ffmpeg is verbose on stderr (banner, stream info,
+    // per-frame progress) and `wait()` reads neither pipe — so once the ~64 KiB pipe buffer
+    // filled, ffmpeg blocked writing, `wait()` never returned, and the call burned the full
+    // timeout. That is not merely slow: the timeout is an `Err`, so after 2 seek positions x
+    // 3 compression attempts the caller soft-deletes a perfectly playable video for a
+    // poster-frame failure. `wait_with_output` polls the pipe and the exit status together.
+    //
+    // It also CONSUMES the child, so the explicit `child.kill()` that used to sit on the
+    // timeout arm cannot exist here — and is not needed: `kill_on_drop(true)` is set above,
+    // and dropping the future on timeout drops the child with it.
+    let out = match tokio::time::timeout(FFMPEG_TIMEOUT, child.wait_with_output()).await {
+        Ok(res) => res.context("ffmpeg wait failed")?,
+        Err(_) => anyhow::bail!("ffmpeg timed out after {}s", FFMPEG_TIMEOUT.as_secs()),
+    };
+
+    // A non-zero exit is not an error (see the doc comment) — the artifact check in
+    // `extract_poster_frame` is the authority. Log the tail so a systematically failing
+    // format is diagnosable without turning it into data loss.
+    if !out.status.success() {
+        tracing::debug!(
+            seek,
+            status = ?out.status,
+            stderr = %tail_lines(&out.stderr, 10),
+            "ffmpeg exited non-zero; the artifact check decides"
+        );
+    }
+    Ok(())
+}
+
+/// Last `n` lines of a child's stderr, lossily decoded.
+///
+/// Bounded on purpose: ffmpeg's stderr is unbounded, and the reason we now drain it is that
+/// unbounded output used to be a hazard. Emitting all of it into a log line — into container
+/// logs that are themselves size-capped — would just move the problem.
+fn tail_lines(bytes: &[u8], n: usize) -> String {
+    let text = String::from_utf8_lossy(bytes);
+    let lines: Vec<&str> = text.lines().filter(|l| !l.trim().is_empty()).collect();
+    lines[lines.len().saturating_sub(n)..].join(" | ")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// The order is the whole fix. `-ss` must precede `-i`, and 0 must be tried after 1 s.
+    #[test]
+    fn the_fallback_seek_exists_and_comes_last() {
+        assert_eq!(
+            SEEK_POSITIONS,
+            &["00:00:01", "0"],
+            "1s first for a better poster, 0 as the fallback that makes short clips work"
+        );
+    }
+
+    /// A missing input yields no frame rather than an error: the caller must degrade to "no
+    /// poster", never fail the upload. `Err` is reserved for a hang or a spawn failure.
+    #[tokio::test]
+    async fn a_missing_source_yields_no_frame_rather_than_an_error() {
+        let dir = std::env::temp_dir().join(format!("es-video-{}", std::process::id()));
+        std::fs::create_dir_all(&dir).unwrap();
+        let dest = dir.join("out.jpg");
+
+        let got = extract_poster_frame(Path::new("/nonexistent/clip.mp4"), &dest, 400).await;
+
+        match got {
+            Ok(false) => {}
+            other => panic!("expected Ok(false) for a missing input, got {other:?}"),
+        }
+        assert!(
+            !dest.exists(),
+            "a failed extraction must leave nothing a caller could mistake for a poster"
+        );
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn the_stderr_tail_is_bounded_and_survives_invalid_utf8() {
+        let noisy: Vec<u8> = (0..500)
+            .map(|i| format!("line {i}\n"))
+            .collect::<String>()
+            .into_bytes();
+        let got = tail_lines(&noisy, 3);
+        assert_eq!(got, "line 497 | line 498 | line 499");
+
+        // ffmpeg emits filenames verbatim, so its stderr is not guaranteed to be UTF-8.
+        assert_eq!(tail_lines(&[b'o', b'k', 0xff], 5), "ok\u{fffd}");
+        assert_eq!(tail_lines(b"", 5), "");
+    }
+
+    /// A real extraction must finish in a small fraction of `FFMPEG_TIMEOUT`.
+    ///
+    /// Wall-clock is the ONLY observable of the bug this guards: piping stderr and then
+    /// calling `wait()` (which drains nothing) blocks ffmpeg on a full pipe buffer until the
+    /// timeout fires, and the timeout is an `Err`, so the upload is soft-deleted. The
+    /// assertion is deliberately on elapsed time, not on the exit status.
+    ///
+    /// Honest limitation: our fixture is quiet enough not to fill a 64 KiB pipe on its own,
+    /// so this catches a regression to `wait()` only in combination with a verbose input. It
+    /// is still worth pinning — a reverted drain plus any chatty clip is data loss.
+    #[tokio::test]
+    async fn a_real_clip_yields_a_poster_well_inside_the_timeout() {
+        if tokio::process::Command::new("ffmpeg")
+            .arg("-version")
+            .stdout(std::process::Stdio::null())
+            .stderr(std::process::Stdio::null())
+            .status()
+            .await
+            .is_err()
+        {
+            eprintln!("skipping: ffmpeg not on PATH");
+            return;
+        }
+        let src = Path::new("../e2e/fixtures/media/sample.mp4");
+        if !src.exists() {
+            eprintln!("skipping: {} missing", src.display());
+            return;
+        }
+
+        let dir = std::env::temp_dir().join(format!("es-video-ok-{}", std::process::id()));
+        std::fs::create_dir_all(&dir).unwrap();
+        let dest = dir.join("poster.jpg");
+
+        let started = std::time::Instant::now();
+        let got = extract_poster_frame(src, &dest, 400).await;
+        let elapsed = started.elapsed();
+
+        assert!(matches!(got, Ok(true)), "expected a poster, got {got:?}");
+        assert!(dest.metadata().unwrap().len() > 0);
+        assert!(
+            elapsed < FFMPEG_TIMEOUT / 4,
+            "extraction took {elapsed:?}; a drained stderr finishes in well under \
+             {FFMPEG_TIMEOUT:?} — this is the pipe-deadlock regression guard"
+        );
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+}

backend/src/state.rs

@@ -3,6 +3,8 @@ use tokio::sync::broadcast;
 
 use crate::config::AppConfig;
 use crate::services::compression::CompressionWorker;
+use crate::services::config::ConfigCache;
+use crate::services::disk::DiskCache;
 use crate::services::rate_limiter::RateLimiter;
 use crate::services::sse_tickets::SseTicketStore;
 
@@ -31,17 +33,27 @@ pub struct AppState {
     pub compression: CompressionWorker,
     pub rate_limiter: RateLimiter,
     pub sse_tickets: SseTicketStore,
+    /// In-memory cache in front of the `config` table. Reads go through here; the
+    /// admin PATCH handler and the test reseed invalidate it after committing.
+    pub config_cache: ConfigCache,
+    /// Cached total/free bytes for the media filesystem (quota + admin stats).
+    pub disk_cache: DiskCache,
 }
 
 impl AppState {
     pub fn new(pool: PgPool, config: AppConfig) -> Self {
-        let (sse_tx, _) = broadcast::channel(256);
+        // Broadcast buffer for live SSE fan-out. Sized to absorb a burst (e.g. many
+        // uploads landing at once during a busy moment) before a slow consumer lags and
+        // has to `resync`. The resync path is a correctness backstop, not the happy path —
+        // a roomier buffer keeps ~1000 concurrent clients from all resyncing at once.
+        let (sse_tx, _) = broadcast::channel(1024);
         let compression = CompressionWorker::new(
             pool.clone(),
             config.media_path.clone(),
             config.compression_concurrency,
             sse_tx.clone(),
         );
+        let config_cache = ConfigCache::new(pool.clone());
         Self {
             pool,
             config,
@@ -49,6 +61,8 @@ impl AppState {
             compression,
             rate_limiter: RateLimiter::new(),
             sse_tickets: SseTicketStore::new(),
+            config_cache,
+            disk_cache: DiskCache::new(),
         }
     }
 }

backend/static/export-viewer/_app/env.js

@@ -1 +0,0 @@
-export const env={}

backend/static/export-viewer/_app/immutable/chunks/BJ__EZ0W.js

@@ -1 +0,0 @@
-import{u as o,n as t,o as c}from"./CcONa1Mr.js";function u(e){throw new Error("https://svelte.dev/e/lifecycle_outside_component")}function r(e){t===null&&u(),o(()=>{const n=c(e);if(typeof n=="function")return n})}export{r as o};

backend/static/export-viewer/_app/immutable/chunks/BRDva_z9.js

@@ -1 +0,0 @@
-import{f as l,g as o,p as u,i as n,j as d,k as m,h as p,e as _,m as v,l as k}from"./CcONa1Mr.js";class w{anchor;#t=new Map;#s=new Map;#e=new Map;#i=new Set;#f=!0;constructor(t,s=!0){this.anchor=t,this.#f=s}#a=t=>{if(this.#t.has(t)){var s=this.#t.get(t),e=this.#s.get(s);if(e)l(e),this.#i.delete(s);else{var f=this.#e.get(s);f&&(this.#s.set(s,f.effect),this.#e.delete(s),f.fragment.lastChild.remove(),this.anchor.before(f.fragment),e=f.effect)}for(const[i,a]of this.#t){if(this.#t.delete(i),i===t)break;const r=this.#e.get(a);r&&(o(r.effect),this.#e.delete(a))}for(const[i,a]of this.#s){if(i===s||this.#i.has(i))continue;const r=()=>{if(Array.from(this.#t.values()).includes(i)){var c=document.createDocumentFragment();v(a,c),c.append(n()),this.#e.set(i,{effect:a,fragment:c})}else o(a);this.#i.delete(i),this.#s.delete(i)};this.#f||!e?(this.#i.add(i),u(a,r,!1)):r()}}};#r=t=>{this.#t.delete(t);const s=Array.from(this.#t.values());for(const[e,f]of this.#e)s.includes(e)||(o(f.effect),this.#e.delete(e))};ensure(t,s){var e=m,f=k();if(s&&!this.#s.has(t)&&!this.#e.has(t))if(f){var i=document.createDocumentFragment(),a=n();i.append(a),this.#e.set(t,{effect:d(()=>s(a)),fragment:i})}else this.#s.set(t,d(()=>s(this.anchor)));if(this.#t.set(e,t),f){for(const[r,h]of this.#s)r===t?e.unskip_effect(h):e.skip_effect(h);for(const[r,h]of this.#e)r===t?e.unskip_effect(h.effect):e.skip_effect(h.effect);e.oncommit(this.#a),e.ondiscard(this.#r)}else p&&(this.anchor=_),this.#a(e)}}export{w as B};

backend/static/export-viewer/_app/immutable/chunks/Bxn6SmGf.js

@@ -1 +0,0 @@
-import{b as c,h as o,a as l,E as b,r as p,s as v,c as g,d,e as m}from"./CcONa1Mr.js";import{B as y}from"./BRDva_z9.js";function k(f,h,_=!1){var n;o&&(n=m,l());var s=new y(f),u=_?b:0;function t(a,r){if(o){var e=p(n);if(a!==parseInt(e.substring(1))){var i=v();g(i),s.anchor=i,d(!1),s.ensure(a,r),d(!0);return}}s.ensure(a,r)}c(()=>{var a=!1;h((r,e=0)=>{a=!0,t(e,r)}),a||t(-1,null)},u)}export{k as i};

backend/static/export-viewer/_app/immutable/chunks/RsTAN2PN.js

@@ -1 +0,0 @@
-import{A as v,i as d,B as l,C as u,D as T,T as p,F as h,h as i,e as s,R as E,a as y,G as g,c as w,H as N}from"./CcONa1Mr.js";const A=globalThis?.window?.trustedTypes&&globalThis.window.trustedTypes.createPolicy("svelte-trusted-html",{createHTML:t=>t});function M(t){return A?.createHTML(t)??t}function x(t){var r=v("template");return r.innerHTML=M(t.replaceAll("<!>","<!---->")),r.content}function n(t,r){var e=l;e.nodes===null&&(e.nodes={start:t,end:r,a:null,t:null})}function b(t,r){var e=(r&p)!==0,f=(r&h)!==0,a,_=!t.startsWith("<!>");return()=>{if(i)return n(s,null),s;a===void 0&&(a=x(_?t:"<!>"+t),e||(a=u(a)));var o=f||T?document.importNode(a,!0):a.cloneNode(!0);if(e){var c=u(o),m=o.lastChild;n(c,m)}else n(o,o);return o}}function C(t=""){if(!i){var r=d(t+"");return n(r,r),r}var e=s;return e.nodeType!==g?(e.before(e=d()),w(e)):N(e),n(e,e),e}function O(){if(i)return n(s,null),s;var t=document.createDocumentFragment(),r=document.createComment(""),e=d();return t.append(r,e),n(r,e),t}function P(t,r){if(i){var e=l;((e.f&E)===0||e.nodes.end===null)&&(e.nodes.end=s),y();return}t!==null&&t.before(r)}const L="5";typeof window<"u"&&((window.__svelte??={}).v??=new Set).add(L);export{P as a,n as b,O as c,b as f,C as t};

backend/static/export-viewer/_app/immutable/entry/start.YjNZv4co.js

@@ -1 +0,0 @@
-import{l as o,a as r}from"../chunks/eAGLaJx1.js";export{o as load_css,r as start};

backend/static/export-viewer/_app/immutable/nodes/0.DLesTSIe.js

@@ -1 +0,0 @@
-import{c as s,a as c}from"../chunks/RsTAN2PN.js";import{b as l,E as p,t as i}from"../chunks/CcONa1Mr.js";import{B as m}from"../chunks/BRDva_z9.js";function u(n,r,...e){var o=new m(n);l(()=>{const t=r()??null;o.ensure(t,t&&(a=>t(a,...e)))},p)}const f=!0,_=!1,g=Object.freeze(Object.defineProperty({__proto__:null,prerender:f,ssr:_},Symbol.toStringTag,{value:"Module"}));function h(n,r){var e=s(),o=i(e);u(o,()=>r.children),c(n,e)}export{h as component,g as universal};

backend/static/export-viewer/_app/immutable/nodes/1.D6Kk4lDA.js

@@ -1 +0,0 @@
-import{a as i,f as h}from"../chunks/RsTAN2PN.js";import{q as g,t as v,v as d,w as l,x as s,y as a,z as x}from"../chunks/CcONa1Mr.js";import{s as o}from"../chunks/Bb9JxzU7.js";import{s as _,p}from"../chunks/eAGLaJx1.js";const $={get error(){return p.error},get status(){return p.status}};_.updated.check;const m=$;var k=h("<h1> </h1> <p> </p>",1);function z(c,f){g(f,!0);var t=k(),r=v(t),n=s(r,!0);a(r);var e=x(r,2),u=s(e,!0);a(e),d(()=>{o(n,m.status),o(u,m.error?.message)}),i(c,t),l()}export{z as component};

backend/static/export-viewer/_app/version.json

@@ -1 +0,0 @@
-{"version":"1778876725548"}

backend/tests/common/mod.rs

@@ -0,0 +1,345 @@
+//! Shared fixtures for the DB-backed integration tests.
+//!
+//! Every helper here executes SQL that is **character-for-character identical** to what `src/`
+//! actually runs (see the `// SRC:` markers). That is the whole point: a paraphrased query is a
+//! query nobody runs, and a test that passes against a paraphrase proves nothing about production.
+
+#![allow(dead_code)] // each integration-test crate uses a different subset of these helpers
+
+use sqlx::PgPool;
+use uuid::Uuid;
+
+/// Insert a bare, unreleased event (epoch 0, uploads open).
+pub async fn seed_event(pool: &PgPool, slug: &str) -> Uuid {
+    sqlx::query_scalar("INSERT INTO event (slug, name) VALUES ($1, $2) RETURNING id")
+        .bind(slug)
+        .bind("Hochzeit")
+        .fetch_one(pool)
+        .await
+        .expect("seed event")
+}
+
+/// Insert a guest with a zeroed byte total.
+pub async fn seed_user(pool: &PgPool, event_id: Uuid, name: &str) -> Uuid {
+    sqlx::query_scalar(
+        "INSERT INTO \"user\" (event_id, display_name, recovery_pin_hash)
+         VALUES ($1, $2, 'x') RETURNING id",
+    )
+    .bind(event_id)
+    .bind(name)
+    .fetch_one(pool)
+    .await
+    .expect("seed user")
+}
+
+/// SRC: `handlers/host.rs::release_gallery` — the claim + epoch bump, verbatim.
+/// Returns the POST-increment epoch, exactly as the handler consumes it.
+pub async fn release_gallery(pool: &PgPool, slug: &str) -> Option<i64> {
+    let claimed: Option<(Uuid, String, i64)> = sqlx::query_as(
+        "UPDATE event
+         SET export_released_at = NOW(),
+             uploads_locked_at  = COALESCE(uploads_locked_at, NOW()),
+             export_epoch       = export_epoch + 1
+         WHERE slug = $1 AND export_released_at IS NULL
+         RETURNING id, name, export_epoch",
+    )
+    .bind(slug)
+    .fetch_optional(pool)
+    .await
+    .expect("release_gallery");
+
+    if let Some((event_id, _, epoch)) = claimed {
+        // The handler arms both jobs in the SAME transaction; for a single-connection fixture the
+        // sequencing is equivalent.
+        let mut conn = pool.acquire().await.expect("acquire");
+        enqueue_types_at_epoch(&mut conn, event_id, epoch, &["zip", "html"]).await;
+        Some(epoch)
+    } else {
+        None
+    }
+}
+
+/// SRC: `handlers/host.rs::open_event` — the one statement that retires an entire generation.
+/// Returns rows affected.
+pub async fn open_event(pool: &PgPool, slug: &str) -> u64 {
+    sqlx::query(
+        "UPDATE event
+         SET uploads_locked_at  = NULL,
+             export_released_at = NULL,
+             export_epoch       = export_epoch + 1
+         WHERE slug = $1 AND (uploads_locked_at IS NOT NULL OR export_released_at IS NOT NULL)",
+    )
+    .bind(slug)
+    .execute(pool)
+    .await
+    .expect("open_event")
+    .rows_affected()
+}
+
+/// SRC: `services/export.rs::enqueue_types_at_epoch` — verbatim upsert.
+pub async fn enqueue_types_at_epoch(
+    conn: &mut sqlx::PgConnection,
+    event_id: Uuid,
+    epoch: i64,
+    types: &[&str],
+) {
+    for export_type in types {
+        sqlx::query(
+            "INSERT INTO export_job (event_id, type, status, progress_pct, epoch)
+             VALUES ($1, $2::export_type, 'pending', 0, $3)
+             ON CONFLICT (event_id, type) DO UPDATE
+                 SET status = 'pending', progress_pct = 0, file_path = NULL,
+                     error_message = NULL, completed_at = NULL,
+                     epoch = EXCLUDED.epoch
+             WHERE export_job.status <> 'done' OR export_job.epoch <> EXCLUDED.epoch",
+        )
+        .bind(event_id)
+        .bind(export_type)
+        .bind(epoch)
+        .execute(&mut *conn)
+        .await
+        .expect("enqueue_types_at_epoch");
+    }
+}
+
+/// SRC: `services/export.rs::claim_job` — verbatim. `true` = we won the generation.
+pub async fn claim_job(pool: &PgPool, event_id: Uuid, export_type: &str, epoch: i64) -> bool {
+    sqlx::query(
+        "UPDATE export_job SET status = 'running'
+         WHERE event_id = $1 AND type = $2::export_type
+           AND epoch = $3 AND status = 'pending'",
+    )
+    .bind(event_id)
+    .bind(export_type)
+    .bind(epoch)
+    .execute(pool)
+    .await
+    .expect("claim_job")
+    .rows_affected()
+        > 0
+}
+
+/// SRC: `services/export.rs::finalize_job` — verbatim. This IS the publish step.
+pub async fn finalize_job(
+    pool: &PgPool,
+    event_id: Uuid,
+    export_type: &str,
+    epoch: i64,
+    file_path: &str,
+) -> bool {
+    sqlx::query(
+        "UPDATE export_job
+         SET status = 'done', progress_pct = 100, file_path = $3, completed_at = NOW()
+         WHERE event_id = $1 AND type = $2::export_type
+           AND epoch = $4 AND status = 'running'",
+    )
+    .bind(event_id)
+    .bind(export_type)
+    .bind(file_path)
+    .bind(epoch)
+    .execute(pool)
+    .await
+    .expect("finalize_job")
+    .rows_affected()
+        > 0
+}
+
+/// SRC: `services/export.rs::update_progress` — verbatim. Doubles as the worker's liveness check:
+/// `false` means "your generation was retired, stop working".
+pub async fn update_progress(
+    pool: &PgPool,
+    event_id: Uuid,
+    export_type: &str,
+    epoch: i64,
+    pct: i16,
+) -> bool {
+    sqlx::query(
+        "UPDATE export_job SET progress_pct = $3
+         WHERE event_id = $1 AND type = $2::export_type
+           AND epoch = $4 AND status = 'running'",
+    )
+    .bind(event_id)
+    .bind(export_type)
+    .bind(pct)
+    .bind(epoch)
+    .execute(pool)
+    .await
+    .expect("update_progress")
+    .rows_affected()
+        > 0
+}
+
+/// SRC: `services/export.rs::invalidate_and_arm` — the ViewerOnly ZIP carry-forward, verbatim.
+/// Returns `rows_affected() == 1`, which is what the production code branches on.
+pub async fn carry_zip_forward(pool: &PgPool, event_id: Uuid, epoch: i64) -> bool {
+    sqlx::query(
+        "UPDATE export_job SET epoch = $2
+         WHERE event_id = $1 AND type = 'zip'::export_type
+           AND status = 'done' AND epoch = $2 - 1",
+    )
+    .bind(event_id)
+    .bind(epoch)
+    .execute(pool)
+    .await
+    .expect("carry_zip_forward")
+    .rows_affected()
+        == 1
+}
+
+/// SRC: `services/export.rs::invalidate_and_arm` — the epoch bump, verbatim.
+pub async fn bump_epoch(pool: &PgPool, slug: &str) -> Option<(Uuid, String, i64)> {
+    sqlx::query_as(
+        "UPDATE event SET export_epoch = export_epoch + 1
+         WHERE slug = $1 AND export_released_at IS NOT NULL
+         RETURNING id, name, export_epoch",
+    )
+    .bind(slug)
+    .fetch_optional(pool)
+    .await
+    .expect("bump_epoch")
+}
+
+/// The event's authoritative epoch.
+pub async fn event_epoch(pool: &PgPool, event_id: Uuid) -> i64 {
+    sqlx::query_scalar("SELECT export_epoch FROM event WHERE id = $1")
+        .bind(event_id)
+        .fetch_one(pool)
+        .await
+        .expect("event_epoch")
+}
+
+/// The raw job row, bypassing `export_current` — what the WORKER sees.
+pub async fn job_row(
+    pool: &PgPool,
+    event_id: Uuid,
+    export_type: &str,
+) -> Option<(String, i64, Option<String>)> {
+    sqlx::query_as(
+        "SELECT status::text, epoch, file_path FROM export_job
+          WHERE event_id = $1 AND type = $2::export_type",
+    )
+    .bind(event_id)
+    .bind(export_type)
+    .fetch_optional(pool)
+    .await
+    .expect("job_row")
+}
+
+/// Does `export_current` expose this job at all? (The view itself, without the `status` filter —
+/// it is what `handlers/admin.rs::export_status` reports to the host UI.)
+pub async fn in_export_current(pool: &PgPool, event_id: Uuid, export_type: &str) -> bool {
+    sqlx::query_scalar::<_, i64>(
+        "SELECT COUNT(*) FROM export_current
+          WHERE event_id = $1 AND type = $2::export_type",
+    )
+    .bind(event_id)
+    .bind(export_type)
+    .fetch_one(pool)
+    .await
+    .expect("in_export_current")
+        > 0
+}
+
+/// THE download predicate. SRC: `handlers/admin.rs::download_export` reads exactly this shape —
+/// `SELECT c.file_path FROM export_current c WHERE ... AND c.status = 'done'`. If this returns
+/// `Some`, a guest can download the keepsake; if `None`, they get a 404.
+pub async fn downloadable(pool: &PgPool, event_id: Uuid, export_type: &str) -> Option<String> {
+    sqlx::query_scalar(
+        "SELECT c.file_path FROM export_current c
+          WHERE c.event_id = $1 AND c.type = $2::export_type AND c.status = 'done'",
+    )
+    .bind(event_id)
+    .bind(export_type)
+    .fetch_optional(pool)
+    .await
+    .expect("downloadable")
+    .flatten()
+}
+
+/// Insert an upload of `size` bytes, optionally already soft-deleted.
+pub async fn seed_upload(
+    pool: &PgPool,
+    event_id: Uuid,
+    user_id: Uuid,
+    size: i64,
+    deleted: bool,
+) -> Uuid {
+    sqlx::query_scalar(
+        "INSERT INTO upload (event_id, user_id, original_path, mime_type,
+                             original_size_bytes, deleted_at)
+         VALUES ($1, $2, 'originals/x.jpg', 'image/jpeg', $3,
+                 CASE WHEN $4 THEN NOW() ELSE NULL END)
+         RETURNING id",
+    )
+    .bind(event_id)
+    .bind(user_id)
+    .bind(size)
+    .bind(deleted)
+    .fetch_one(pool)
+    .await
+    .expect("seed upload")
+}
+
+/// Flip the moderation flags a ban sets.
+pub async fn set_user_moderation(pool: &PgPool, user_id: Uuid, banned: bool, hidden: bool) {
+    sqlx::query("UPDATE \"user\" SET is_banned = $2, uploads_hidden = $3 WHERE id = $1")
+        .bind(user_id)
+        .bind(banned)
+        .bind(hidden)
+        .execute(pool)
+        .await
+        .expect("set moderation");
+}
+
+/// SRC: `services/export.rs::query_uploads` — the visibility filter, verbatim, projected down to
+/// `(id, original_size_bytes)`. This is the row set that ACTUALLY lands in the archives.
+///
+/// Production builds this WHERE from `export_visibility_where!()`, shared with
+/// `estimate_export_bytes`. A copy here can pin the behaviour but CANNOT detect production moving
+/// away from it — that is what sharing the fragment is for, not this.
+pub async fn export_visible_uploads(pool: &PgPool, event_id: Uuid) -> Vec<(Uuid, i64)> {
+    sqlx::query_as(
+        "SELECT u.id, u.original_size_bytes
+         FROM upload u
+         JOIN \"user\" usr ON usr.id = u.user_id
+         WHERE u.event_id = $1 AND u.deleted_at IS NULL
+           AND usr.uploads_hidden = FALSE AND usr.is_banned = FALSE
+         GROUP BY u.id, usr.display_name
+         ORDER BY u.created_at ASC",
+    )
+    .bind(event_id)
+    .fetch_all(pool)
+    .await
+    .expect("export_visible_uploads")
+}
+
+/// SRC: `services/export.rs::estimate_export_bytes` — verbatim. Same caveat as above: production
+/// shares its WHERE with `query_uploads` via `export_visibility_where!()`, so these two copies
+/// agreeing proves the behaviour, not the absence of drift.
+pub async fn estimate_export_bytes(pool: &PgPool, event_id: Uuid) -> i64 {
+    let (bytes,): (i64,) = sqlx::query_as(
+        "SELECT COALESCE(SUM(u.original_size_bytes), 0)::bigint
+           FROM upload u
+           JOIN \"user\" usr ON usr.id = u.user_id
+          WHERE u.event_id = $1 AND u.deleted_at IS NULL
+            AND usr.uploads_hidden = FALSE AND usr.is_banned = FALSE",
+    )
+    .bind(event_id)
+    .fetch_one(pool)
+    .await
+    .expect("estimate_export_bytes");
+    bytes
+}
+
+/// SRC: `services/export.rs::ensure_export_space` — the armed-job count, verbatim.
+pub async fn armed_job_count(pool: &PgPool, event_id: Uuid) -> i64 {
+    let (n,): (i64,) = sqlx::query_as(
+        "SELECT COUNT(*) FROM export_job
+          WHERE event_id = $1 AND status IN ('pending', 'running')",
+    )
+    .bind(event_id)
+    .fetch_one(pool)
+    .await
+    .expect("armed_job_count");
+    n
+}

backend/tests/export_epoch.rs

@@ -0,0 +1,435 @@
+//! DB-backed integration tests for the export epoch state machine (migration 014).
+//!
+//! These run against a REAL Postgres: `#[sqlx::test]` creates a throwaway database per test and
+//! runs `backend/migrations/` into it, so the schema, the enums, the `UNIQUE (event_id, type)`
+//! constraint and the `export_current` view are the production ones — not a mock.
+//!
+//! THE INVARIANT, from migration 014:
+//!
+//!     An export is downloadable IFF
+//!         event.export_released_at IS NOT NULL
+//!     AND export_job.epoch = event.export_epoch
+//!     AND export_job.status = 'done'
+//!
+//! Readiness is DERIVED (the `export_current` view), never stored. Every test below pins one leg of
+//! that invariant with the exact SQL `src/` executes (see `tests/common/mod.rs`).
+
+mod common;
+
+use common::*;
+use sqlx::PgPool;
+
+// ─────────────────────────────────────────────────────────────────────────────
+// 1. Epoch monotonicity
+// ─────────────────────────────────────────────────────────────────────────────
+
+/// Release, reopen and re-release each bump `export_epoch`, and `RETURNING export_epoch` hands the
+/// caller the POST-increment value.
+///
+/// PREVENTS: a worker born with the PRE-increment epoch. It would be inert from the instant it
+/// started — every one of its writes is `epoch`-guarded, so `claim_job`/`finalize_job` would match
+/// nothing, the job row would sit at `pending` 0% forever with no live worker, and the host's
+/// download button would spin and then 404. The keepsake would never be built at all.
+#[sqlx::test]
+async fn release_returns_post_increment_epoch(pool: PgPool) {
+    let event_id = seed_event(&pool, "wedding").await;
+    assert_eq!(
+        event_epoch(&pool, event_id).await,
+        0,
+        "a fresh event starts at epoch 0"
+    );
+
+    let released = release_gallery(&pool, "wedding")
+        .await
+        .expect("release claims the event");
+    assert_eq!(
+        released, 1,
+        "RETURNING must give the epoch AFTER the +1, not before"
+    );
+    assert_eq!(
+        event_epoch(&pool, event_id).await,
+        released,
+        "worker's epoch == event's epoch"
+    );
+
+    // The jobs armed by the release carry exactly that epoch — this is what makes the worker's
+    // guarded writes match.
+    for t in ["zip", "html"] {
+        let (status, epoch, _) = job_row(&pool, event_id, t).await.expect("job armed");
+        assert_eq!(status, "pending");
+        assert_eq!(
+            epoch, released,
+            "{t} job must be armed at the epoch the worker was born with"
+        );
+    }
+}
+
+/// Epoch is strictly monotonic across the whole release/reopen/re-release cycle, and a second
+/// release attempt while already released is rejected WITHOUT bumping.
+///
+/// PREVENTS: epoch reuse. If a reopen could return the event to an epoch some old `done` row still
+/// carries, a retired keepsake — one that a guest asked to be taken down from — would silently
+/// become downloadable again.
+#[sqlx::test]
+async fn epoch_is_strictly_monotonic_across_reopen(pool: PgPool) {
+    let event_id = seed_event(&pool, "wedding").await;
+
+    assert_eq!(release_gallery(&pool, "wedding").await, Some(1));
+
+    // A duplicate release is a no-op (`WHERE export_released_at IS NULL`) and must NOT bump.
+    assert_eq!(
+        release_gallery(&pool, "wedding").await,
+        None,
+        "already released"
+    );
+    assert_eq!(
+        event_epoch(&pool, event_id).await,
+        1,
+        "a rejected release must not move the epoch"
+    );
+
+    // Reopen retires the generation with ONE write.
+    assert_eq!(open_event(&pool, "wedding").await, 1);
+    assert_eq!(event_epoch(&pool, event_id).await, 2, "reopen bumps");
+
+    // And re-releasing bumps again — never back to 1.
+    assert_eq!(
+        release_gallery(&pool, "wedding").await,
+        Some(3),
+        "re-release bumps again"
+    );
+    assert_eq!(event_epoch(&pool, event_id).await, 3);
+}
+
+// ─────────────────────────────────────────────────────────────────────────────
+// 2. A retired-epoch worker is inert
+// ─────────────────────────────────────────────────────────────────────────────
+
+/// A worker holding a retired epoch cannot write anything anybody can see: once the rows have been
+/// re-armed at a newer epoch, its `update_progress` and `finalize_job` both match 0 rows, and
+/// `export_current` never exposes its output.
+///
+/// PREVENTS: the classic lost race — a slow worker from BEFORE a takedown finishing afterwards and
+/// publishing an archive that still contains the photo a guest asked to have removed. "Please take
+/// my photo out" is the one request that most needs to reach the keepsake, and the keepsake is the
+/// artifact people keep forever.
+#[sqlx::test]
+async fn retired_epoch_worker_writes_are_no_ops(pool: PgPool) {
+    let event_id = seed_event(&pool, "wedding").await;
+    let old_epoch = release_gallery(&pool, "wedding").await.unwrap();
+
+    // Worker A is born at epoch 1 and claims the ZIP.
+    assert!(
+        claim_job(&pool, event_id, "zip", old_epoch).await,
+        "worker A wins its claim"
+    );
+    assert!(
+        update_progress(&pool, event_id, "zip", old_epoch, 40).await,
+        "still live at 40%"
+    );
+
+    // ── A takedown lands mid-export: `invalidate_and_arm(Affects::Both)` bumps and re-arms. ──
+    let (_, _, new_epoch) = bump_epoch(&pool, "wedding")
+        .await
+        .expect("bump on a released event");
+    assert_eq!(new_epoch, old_epoch + 1);
+    let mut conn = pool.acquire().await.unwrap();
+    enqueue_types_at_epoch(&mut conn, event_id, new_epoch, &["zip", "html"]).await;
+    drop(conn);
+
+    // Worker A is now INERT BY CONSTRUCTION. Every write is guarded on its own birth epoch.
+    assert!(
+        !update_progress(&pool, event_id, "zip", old_epoch, 90).await,
+        "the liveness check must report `false` so worker A stops grinding through the gallery"
+    );
+    assert!(
+        !finalize_job(&pool, event_id, "zip", old_epoch, "exports/Gallery.1.zip").await,
+        "worker A's finalize MUST affect 0 rows — this is the write that would have published a \
+         keepsake still containing the taken-down photo"
+    );
+
+    // The re-armed row is untouched by the loser: still pending at the LIVE epoch, waiting for the
+    // fresh worker. (If worker A had won, this row would read `done` at epoch 1.)
+    let (status, epoch, file_path) = job_row(&pool, event_id, "zip").await.unwrap();
+    assert_eq!((status.as_str(), epoch), ("pending", new_epoch));
+    assert_eq!(
+        file_path, None,
+        "the loser's file_path must never be recorded"
+    );
+
+    // And nothing is downloadable — not the stale archive, not anything.
+    assert_eq!(downloadable(&pool, event_id, "zip").await, None);
+}
+
+/// The documented, deliberate nuance in `claim_job`: after a bare `open_event` (which writes
+/// NOTHING to `export_job` — that is the point of the design), a worker at the old epoch still WINS
+/// its claim and can still write `done`. That is wasted work, not incorrectness: retirement is
+/// enforced at READ time. `export_current` must refuse to expose the row.
+///
+/// PREVENTS: someone "optimising" `claim_job` into a cross-table `EXISTS (SELECT ... FROM event)`
+/// guard — the exact unsound guard migration 014 removed (under READ COMMITTED, a blocked UPDATE
+/// re-evaluates same-row predicates but answers other-table subqueries from a stale snapshot).
+/// This test pins the read-time enforcement so the write-time guard is never re-added.
+#[sqlx::test]
+async fn reopen_retires_at_read_time_not_write_time(pool: PgPool) {
+    let event_id = seed_event(&pool, "wedding").await;
+    let epoch = release_gallery(&pool, "wedding").await.unwrap();
+
+    assert!(claim_job(&pool, event_id, "zip", epoch).await);
+
+    // Host reopens uploads. No export_job row is touched.
+    assert_eq!(open_event(&pool, "wedding").await, 1);
+
+    // The in-flight worker's row-local writes still match — it was never told to stop.
+    assert!(
+        finalize_job(&pool, event_id, "zip", epoch, "exports/Gallery.1.zip").await,
+        "documented: the claim/finalize is guarded on the JOB row's epoch, not the event's"
+    );
+    let (status, _, _) = job_row(&pool, event_id, "zip").await.unwrap();
+    assert_eq!(status, "done", "the row really does say done");
+
+    // …and yet it is invisible. `export_current` requires the event to be released AND the epochs to
+    // match; the reopen broke both. A worker at a dead epoch writes a row nobody can see.
+    assert!(!in_export_current(&pool, event_id, "zip").await);
+    assert_eq!(
+        downloadable(&pool, event_id, "zip").await,
+        None,
+        "a reopened event must serve NO keepsake, however finished the job row looks"
+    );
+}
+
+// ─────────────────────────────────────────────────────────────────────────────
+// 3. `export_current` exactness (table-driven)
+// ─────────────────────────────────────────────────────────────────────────────
+
+/// The view is the ONE definition of "downloadable". Released + `done` + matching epoch ⇒ present;
+/// break ANY single leg ⇒ absent. Nothing else may make it appear or disappear.
+///
+/// PREVENTS, leg by leg:
+///  * `released` — serving a keepsake for an event whose uploads are still open, i.e. an archive
+///    missing every photo taken after the snapshot.
+///  * `done` — handing out a half-written ZIP (a corrupt keepsake, downloaded once, kept forever).
+///  * `epoch` — the retired-generation download: the 404-forever keepsake, or worse, the archive
+///    still containing content that was taken down.
+#[sqlx::test]
+async fn export_current_is_exactly_the_invariant(pool: PgPool) {
+    // (name, released?, status, job epoch offset from the event epoch, expected visible)
+    let cases: &[(&str, bool, &str, i64, bool)] = &[
+        ("released + done + current epoch", true, "done", 0, true),
+        (
+            "NOT released (done, epoch matches)",
+            false,
+            "done",
+            0,
+            false,
+        ),
+        ("NOT done: pending", true, "pending", 0, false),
+        ("NOT done: running", true, "running", 0, false),
+        ("NOT done: failed", true, "failed", 0, false),
+        ("stale epoch (done, released)", true, "done", -1, false),
+        ("future epoch (done, released)", true, "done", 1, false),
+        (
+            "migration-014 retired sentinel epoch -1",
+            true,
+            "done",
+            -2,
+            false,
+        ),
+    ];
+
+    for (i, (name, released, status, offset, expect_visible)) in cases.iter().enumerate() {
+        let slug = format!("case{i}");
+        let event_id = seed_event(&pool, &slug).await;
+
+        // Get the event to a known epoch (1) either by releasing it, or — for the unreleased case —
+        // by releasing and reopening, which leaves it unreleased at a non-zero epoch.
+        let event_epoch_now = if *released {
+            release_gallery(&pool, &slug).await.unwrap()
+        } else {
+            release_gallery(&pool, &slug).await.unwrap();
+            open_event(&pool, &slug).await;
+            event_epoch(&pool, event_id).await
+        };
+
+        // Plant a single ZIP job row in the exact state under test. `-2` encodes "the sentinel the
+        // migration stamps on retired rows", which must never equal a non-negative event epoch.
+        // (Clear the rows the release armed first — `UNIQUE (event_id, type)`.)
+        sqlx::query("DELETE FROM export_job WHERE event_id = $1")
+            .bind(event_id)
+            .execute(&pool)
+            .await
+            .expect("clear armed jobs");
+
+        let job_epoch = if *offset == -2 {
+            -1
+        } else {
+            event_epoch_now + offset
+        };
+        sqlx::query(
+            "INSERT INTO export_job (event_id, type, status, progress_pct, epoch, file_path)
+             VALUES ($1, 'zip', $2::export_status, 100, $3, 'exports/Gallery.zip')",
+        )
+        .bind(event_id)
+        .bind(*status)
+        .bind(job_epoch)
+        .execute(&pool)
+        .await
+        .expect("plant job row");
+
+        let visible = downloadable(&pool, event_id, "zip").await.is_some();
+        assert_eq!(
+            visible, *expect_visible,
+            "export_current exactness violated for case: {name} \
+             (released={released}, status={status}, job_epoch={job_epoch}, event_epoch={event_epoch_now})"
+        );
+    }
+}
+
+// ─────────────────────────────────────────────────────────────────────────────
+// 4. The ViewerOnly ZIP carry-forward
+// ─────────────────────────────────────────────────────────────────────────────
+
+/// Branch A — the ZIP is `done` at the outgoing epoch: the carry-forward re-stamps it to the new
+/// epoch (rows_affected = 1), so only the HTML viewer is rebuilt and the finished ZIP stays
+/// downloadable throughout.
+///
+/// PREVENTS: rebuilding a multi-GB archive because someone deleted a comment. The ZIP holds media,
+/// not comments — a needless rebuild would 404 the photo download for minutes to change nothing
+/// inside it.
+#[sqlx::test]
+async fn viewer_only_carries_a_done_zip_forward(pool: PgPool) {
+    let event_id = seed_event(&pool, "wedding").await;
+    let e1 = release_gallery(&pool, "wedding").await.unwrap();
+
+    // Both halves finish at epoch 1 — the keepsake is live.
+    for t in ["zip", "html"] {
+        assert!(claim_job(&pool, event_id, t, e1).await);
+        assert!(finalize_job(&pool, event_id, t, e1, &format!("exports/{t}.{e1}.zip")).await);
+    }
+    let zip_file = downloadable(&pool, event_id, "zip")
+        .await
+        .expect("zip is live");
+
+    // ── A comment is moderated: invalidate_and_arm(Affects::ViewerOnly). ──
+    let (_, _, e2) = bump_epoch(&pool, "wedding").await.unwrap();
+    let carried = carry_zip_forward(&pool, event_id, e2).await;
+    assert!(
+        carried,
+        "a `done` ZIP at epoch-1 MUST be carried forward (rows_affected == 1)"
+    );
+
+    // Only the viewer is re-armed…
+    let mut conn = pool.acquire().await.unwrap();
+    enqueue_types_at_epoch(&mut conn, event_id, e2, &["html"]).await;
+    drop(conn);
+
+    // …and the ZIP is STILL DOWNLOADABLE, at the new epoch, pointing at the same, unrenamed file.
+    let (status, epoch, _) = job_row(&pool, event_id, "zip").await.unwrap();
+    assert_eq!(
+        (status.as_str(), epoch),
+        ("done", e2),
+        "the ZIP row rode the epoch bump"
+    );
+    assert_eq!(
+        downloadable(&pool, event_id, "zip").await,
+        Some(zip_file),
+        "the carried archive must never stop being served — same file, new epoch"
+    );
+
+    // The viewer, meanwhile, is correctly retired and pending a rebuild.
+    assert_eq!(job_row(&pool, event_id, "html").await.unwrap().0, "pending");
+    assert_eq!(downloadable(&pool, event_id, "html").await, None);
+}
+
+/// Branch B — THE BUG WE JUST FIXED. If the ZIP is still `pending`/`running` when the comment is
+/// moderated (which is MINUTES for a real multi-GB gallery, and deleting a comment right after
+/// release is an utterly ordinary thing to do), the carry-forward matches NOTHING
+/// (rows_affected = 0) — so the caller must NOT assume it carried, and must re-arm the ZIP too.
+///
+/// PREVENTS: the stranded ZIP. Blindly re-arming only the viewer would leave the ZIP row at the
+/// retired epoch; the in-flight worker then finishes and writes `done` at an epoch `export_current`
+/// no longer matches, nothing ever re-arms it, and `GET /export/zip` 404s FOREVER — a keepsake the
+/// couple paid for that simply never appears, short of a reboot.
+#[sqlx::test]
+async fn viewer_only_carry_forward_matches_nothing_when_zip_unfinished(pool: PgPool) {
+    for zip_state in ["pending", "running"] {
+        let slug = format!("wedding-{zip_state}");
+        let event_id = seed_event(&pool, &slug).await;
+        let e1 = release_gallery(&pool, &slug).await.unwrap();
+
+        // The ZIP worker is still going; only the viewer has finished.
+        if zip_state == "running" {
+            assert!(claim_job(&pool, event_id, "zip", e1).await);
+        }
+        assert!(claim_job(&pool, event_id, "html", e1).await);
+        assert!(finalize_job(&pool, event_id, "html", e1, "exports/Memories.1.zip").await);
+
+        // ── The comment is moderated. ──
+        let (_, _, e2) = bump_epoch(&pool, &slug).await.unwrap();
+        let carried = carry_zip_forward(&pool, event_id, e2).await;
+
+        assert!(
+            !carried,
+            "a {zip_state} ZIP has nothing to carry forward — the UPDATE must affect 0 rows \
+             (its `status = 'done'` predicate is the whole precondition)"
+        );
+
+        // The carry-forward's OWN result decides. It didn't match ⇒ rebuild the ZIP as well.
+        let types: &[&str] = if carried { &["html"] } else { &["zip", "html"] };
+        let mut conn = pool.acquire().await.unwrap();
+        enqueue_types_at_epoch(&mut conn, event_id, e2, types).await;
+        drop(conn);
+
+        // THE ASSERTION THAT WOULD HAVE CAUGHT THE BUG: the ZIP must not be stranded at the dead
+        // epoch. It is re-armed at the live one, so a fresh worker will actually build it.
+        let (status, epoch, _) = job_row(&pool, event_id, "zip").await.unwrap();
+        assert_eq!(
+            (status.as_str(), epoch),
+            ("pending", e2),
+            "the unfinished ZIP MUST be re-armed at the new epoch, not left stranded at {e1}"
+        );
+
+        // Even if the old in-flight worker now "finishes", it is inert and cannot resurrect itself.
+        assert!(!finalize_job(&pool, event_id, "zip", e1, "exports/Gallery.1.zip").await);
+        assert_eq!(downloadable(&pool, event_id, "zip").await, None);
+    }
+}
+
+/// The re-arm upsert must never clobber the archive it just carried forward.
+///
+/// `enqueue_types_at_epoch`'s `WHERE export_job.status <> 'done' OR export_job.epoch <> EXCLUDED.epoch`
+/// is the "startup recovery must not clobber a good half" rule, expressed as the readiness predicate
+/// itself. PREVENTS: boot recovery resetting a perfectly good, downloadable ZIP back to `pending`
+/// and making the keepsake 404 while it needlessly rebuilds.
+#[sqlx::test]
+async fn enqueue_preserves_a_done_half_at_the_current_epoch(pool: PgPool) {
+    let event_id = seed_event(&pool, "wedding").await;
+    let e1 = release_gallery(&pool, "wedding").await.unwrap();
+
+    // The ZIP finished; the HTML worker was killed mid-flight (crash) and sits at `running`.
+    assert!(claim_job(&pool, event_id, "zip", e1).await);
+    assert!(finalize_job(&pool, event_id, "zip", e1, "exports/Gallery.1.zip").await);
+    assert!(claim_job(&pool, event_id, "html", e1).await);
+
+    // Boot recovery re-arms both types at the SAME epoch.
+    let mut conn = pool.acquire().await.unwrap();
+    enqueue_types_at_epoch(&mut conn, event_id, e1, &["zip", "html"]).await;
+    drop(conn);
+
+    // The good half survives untouched…
+    let (status, epoch, file_path) = job_row(&pool, event_id, "zip").await.unwrap();
+    assert_eq!(
+        (status.as_str(), epoch),
+        ("done", e1),
+        "a done half at the live epoch is preserved"
+    );
+    assert_eq!(
+        file_path.as_deref(),
+        Some("exports/Gallery.1.zip"),
+        "file_path not nulled"
+    );
+    assert!(downloadable(&pool, event_id, "zip").await.is_some());
+
+    // …and only the missing half is re-armed.
+    assert_eq!(job_row(&pool, event_id, "html").await.unwrap().0, "pending");
+}

backend/tests/export_preflight.rs

@@ -0,0 +1,163 @@
+//! DB-backed tests for the export disk preflight.
+//!
+//! The keepsake used to be built with NO free-space check at all, and the failure that produced was
+//! not "the export failed" but "the deliverable is stuck and the escape hatch needs the space that
+//! isn't there":
+//!
+//!   1. A takedown bumps the epoch and re-arms both halves.
+//!   2. The ZIP hits ENOSPC partway through a multi-GB write.
+//!   3. The job row is now `failed` at the CURRENT epoch, so readiness
+//!      (`epoch = event.export_epoch AND status = 'done'`) is false and `GET /export/zip` 404s —
+//!      while the last good archive sits on disk, unreferenced and unreachable.
+//!   4. `POST /host/export/rebuild` re-arms the same doomed write.
+//!
+//! Two changes close it: reclaim the superseded generation BEFORE building (so peak usage is one
+//! generation, not two) and refuse up front with a number the host can act on.
+//!
+//! What these tests pin is the ESTIMATE — the part that decides. The arithmetic on top of it lives
+//! in `services/export.rs`'s unit tests; the filesystem selection lives in `is_superseded_archive`.
+//!
+//! ON DRIFT, precisely, because it is easy to overclaim here. The hazard is that `query_uploads`
+//! (which selects the rows the archives are built from) and `estimate_export_bytes` (which sizes
+//! them) could disagree — and an estimate missing rows the archive writes UNDER-reserves, the one
+//! direction that reintroduces the ENOSPC. **These tests cannot catch that**, and neither can any
+//! test in this harness: both sides here are `SRC:`-marked hand-copies in `tests/common/mod.rs`,
+//! so if production moved and the copies didn't, they would sit still and keep passing.
+//!
+//! That is fixed where it can be — the two queries now share one `export_visibility_where!()`
+//! fragment in `services/export.rs`, so they cannot diverge by construction. What is left for
+//! these tests is what the convention is genuinely good at: pinning the BEHAVIOUR, so a change
+//! that deliberately alters the filter has to come here and say so.
+
+mod common;
+
+use common::*;
+use sqlx::PgPool;
+
+/// The estimate must equal the sum over EXACTLY the rows `query_uploads` returns — computed from
+/// that row set, not from a restatement of its WHERE clause.
+///
+/// PINS: which uploads the preflight is allowed to count. Each excluded row below is excluded by a
+/// DIFFERENT predicate, so a change that drops or weakens any one of them fails here and has to be
+/// argued for. (It does not detect production drifting away from these copies — see the file
+/// header; `export_visibility_where!()` is what makes that impossible.)
+#[sqlx::test]
+async fn the_estimate_sums_exactly_the_rows_the_archive_will_contain(pool: PgPool) {
+    let event_id = seed_event(&pool, "wedding").await;
+
+    let visible = seed_user(&pool, event_id, "Anna").await;
+    let banned = seed_user(&pool, event_id, "Ben").await;
+    let hidden = seed_user(&pool, event_id, "Cara").await;
+
+    seed_upload(&pool, event_id, visible, 1_000, false).await;
+    seed_upload(&pool, event_id, visible, 2_500, false).await;
+    // Each of these is excluded from the archive by a DIFFERENT predicate.
+    seed_upload(&pool, event_id, visible, 9_000, true).await; // soft-deleted
+    seed_upload(&pool, event_id, banned, 9_000, false).await; // uploader banned
+    seed_upload(&pool, event_id, hidden, 9_000, false).await; // uploads hidden
+
+    set_user_moderation(&pool, banned, true, true).await;
+    set_user_moderation(&pool, hidden, false, true).await;
+
+    let rows = export_visible_uploads(&pool, event_id).await;
+    let expected: i64 = rows.iter().map(|(_, bytes)| bytes).sum();
+
+    assert_eq!(rows.len(), 2, "only Anna's two live uploads are archived");
+    assert_eq!(
+        estimate_export_bytes(&pool, event_id).await,
+        expected,
+        "the preflight must size the gallery the export will actually write"
+    );
+    assert_eq!(expected, 3_500);
+}
+
+/// An event with nothing to archive estimates zero rather than NULL.
+///
+/// PREVENTS: `SUM()` over no rows returning NULL and the decode blowing up — which would abort the
+/// export with a type error instead of building an (entirely legitimate) empty keepsake.
+#[sqlx::test]
+async fn an_empty_gallery_estimates_zero_not_null(pool: PgPool) {
+    let event_id = seed_event(&pool, "wedding").await;
+    assert_eq!(estimate_export_bytes(&pool, event_id).await, 0);
+
+    // And with a user who has uploaded nothing.
+    seed_user(&pool, event_id, "Anna").await;
+    assert_eq!(estimate_export_bytes(&pool, event_id).await, 0);
+}
+
+/// A release arms both halves, so the preflight sees a count of 2 and reserves for the pair.
+///
+/// PREVENTS: the concurrency under-reservation. `spawn_export_jobs` starts the ZIP and HTML workers
+/// at the same instant, and BOTH are gallery-sized (`Memories.zip` streams the original for every
+/// video and every image at or under 5 MB, all `Compression::Stored`). A worker reserving only for
+/// itself would see "it fits", its sibling would independently see the same, and together they
+/// would ENOSPC — which is why `required_free_bytes` multiplies by this count.
+#[sqlx::test]
+async fn a_release_arms_both_halves_so_the_preflight_reserves_for_two(pool: PgPool) {
+    let event_id = seed_event(&pool, "wedding").await;
+    let user = seed_user(&pool, event_id, "Anna").await;
+    seed_upload(&pool, event_id, user, 1_000, false).await;
+
+    assert_eq!(
+        armed_job_count(&pool, event_id).await,
+        0,
+        "nothing is armed before the release"
+    );
+
+    let epoch = release_gallery(&pool, "wedding").await.expect("released");
+    assert_eq!(
+        armed_job_count(&pool, event_id).await,
+        2,
+        "a release arms zip AND html — both compete for the same disk"
+    );
+
+    // A worker that has claimed its half is still competing; `running` must keep counting.
+    assert!(claim_job(&pool, event_id, "zip", epoch).await);
+    assert_eq!(
+        armed_job_count(&pool, event_id).await,
+        2,
+        "claiming moves pending -> running, which must not drop out of the reservation"
+    );
+
+    // Only a FINISHED half stops competing.
+    assert!(finalize_job(&pool, event_id, "zip", epoch, "exports/Gallery.zip").await);
+    assert_eq!(
+        armed_job_count(&pool, event_id).await,
+        1,
+        "a done half no longer needs space reserved for it"
+    );
+}
+
+/// A ViewerOnly regeneration re-arms only the HTML half, so the preflight reserves for one.
+///
+/// PREVENTS: over-reservation refusing a rebuild that fits perfectly well. Moderating a comment
+/// carries the finished ZIP forward untouched; demanding room for a second copy of it would fail
+/// the one operation that needs no new gallery-sized write at all.
+#[sqlx::test]
+async fn a_viewer_only_regeneration_reserves_for_one_half(pool: PgPool) {
+    let event_id = seed_event(&pool, "wedding").await;
+    let user = seed_user(&pool, event_id, "Anna").await;
+    seed_upload(&pool, event_id, user, 1_000, false).await;
+
+    let epoch = release_gallery(&pool, "wedding").await.expect("released");
+    for t in ["zip", "html"] {
+        assert!(claim_job(&pool, event_id, t, epoch).await);
+        assert!(finalize_job(&pool, event_id, t, epoch, &format!("exports/{t}")).await);
+    }
+    assert_eq!(armed_job_count(&pool, event_id).await, 0);
+
+    // A moderated comment: bump the epoch, carry the ZIP forward, re-arm only the viewer.
+    let (_, _, next) = bump_epoch(&pool, "wedding").await.expect("bumped");
+    assert!(
+        carry_zip_forward(&pool, event_id, next).await,
+        "the finished ZIP is re-stamped, not rebuilt"
+    );
+    let mut conn = pool.acquire().await.expect("acquire");
+    enqueue_types_at_epoch(&mut conn, event_id, next, &["html"]).await;
+
+    assert_eq!(
+        armed_job_count(&pool, event_id).await,
+        1,
+        "only the viewer is being rebuilt, so only one archive's worth of space is needed"
+    );
+}

backend/tests/failed_original_sweep.rs

@@ -0,0 +1,352 @@
+//! DB-backed tests for the deleted-media sweep (`services/maintenance.rs`).
+//!
+//! Context, in two halves.
+//!
+//! The compression worker deliberately no longer deletes an upload's original when its transcode
+//! fails — a transient ENOSPC or a codec panic must never destroy the only copy of a photo a guest
+//! cannot retake. But the row is soft-deleted and the uploader's quota IS refunded, so those bytes
+//! become invisible, unowned and free.
+//!
+//! The SAME hole was reachable by the ordinary path, and that one is not an edge case at all:
+//! `soft_delete_in_event` refunds `total_upload_bytes` on every guest or host delete and nothing
+//! removed the files, so the quota stopped bounding the disk. Upload 500 MB, delete, quota back to
+//! zero, upload another 500 MB — a guest curating their camera roll, which is what people do. The
+//! sweep used to reach only `compression_status = 'failed'`, so it never touched this case; the
+//! test below that now asserts an owner-deleted upload IS reclaimed is the one that used to assert
+//! the opposite.
+//!
+//! Two windows, because the two deletes mean different things: 14 days for a failure an operator
+//! may want to investigate, 24 hours for a removal someone asked for (14 days outlives the whole
+//! event, so a deliberate delete would never reclaim anything while it mattered).
+//!
+//! The selection predicate is the whole safety argument — it must reach both leftovers and never a
+//! live upload — so that is what these pin, following the same "reproduce the SQL verbatim" pattern
+//! as `upload_concurrency.rs`. `#[sqlx::test]` gives each test a fresh, migrated database.
+
+mod common;
+
+use common::*;
+use sqlx::PgPool;
+use uuid::Uuid;
+
+const FAILED_DAYS: i64 = 14;
+const DELETED_HOURS: i64 = 24;
+
+/// SRC: `services/maintenance.rs::cleanup_deleted_media` — the selection, verbatim.
+async fn sweep_selects(pool: &PgPool, failed_days: i64, deleted_hours: i64) -> Vec<Uuid> {
+    type Row = (Uuid, String, Option<String>, Option<String>, Option<String>);
+    sqlx::query_as::<_, Row>(
+        "SELECT id, original_path, preview_path, display_path, thumbnail_path FROM upload
+         WHERE deleted_at IS NOT NULL
+           AND CASE WHEN compression_status = 'failed'
+                    THEN deleted_at < NOW() - ($1 || ' days')::interval
+                    ELSE deleted_at < NOW() - ($2 || ' hours')::interval
+               END
+           AND (original_path <> '' OR preview_path IS NOT NULL
+                OR display_path IS NOT NULL OR thumbnail_path IS NOT NULL)",
+    )
+    .bind(failed_days.to_string())
+    .bind(deleted_hours.to_string())
+    .fetch_all(pool)
+    .await
+    .expect("sweep query")
+    .into_iter()
+    .map(|(id, ..)| id)
+    .collect()
+}
+
+/// Seed an upload aged `deleted_hours_ago` (None = live), with optional derivative paths.
+async fn seed_aged_upload(
+    pool: &PgPool,
+    event_id: Uuid,
+    user_id: Uuid,
+    status: &str,
+    deleted_hours_ago: Option<i64>,
+    original_path: &str,
+    derivatives: bool,
+) -> Uuid {
+    sqlx::query_scalar(
+        "INSERT INTO upload (event_id, user_id, original_path, mime_type, original_size_bytes,
+                             compression_status, deleted_at,
+                             preview_path, display_path, thumbnail_path)
+         VALUES ($1, $2, $3, 'image/jpeg', 1000, $4,
+                 CASE WHEN $5::bigint IS NULL THEN NULL
+                      ELSE NOW() - ($5::text || ' hours')::interval END,
+                 CASE WHEN $6 THEN 'previews/p.jpg' END,
+                 CASE WHEN $6 THEN 'displays/d.jpg' END,
+                 CASE WHEN $6 THEN 'thumbs/t.jpg' END)
+         RETURNING id",
+    )
+    .bind(event_id)
+    .bind(user_id)
+    .bind(original_path)
+    .bind(status)
+    .bind(deleted_hours_ago)
+    .bind(derivatives)
+    .fetch_one(pool)
+    .await
+    .expect("seed upload")
+}
+
+/// A live upload is untouchable no matter how the windows are configured.
+///
+/// PREVENTS: the catastrophic loosening. Everything else here is about reclaiming more; this is the
+/// one assertion that must never bend.
+#[sqlx::test]
+async fn a_live_upload_is_never_selected(pool: PgPool) {
+    let event_id = seed_event(&pool, "sweep-live").await;
+    let user_id = seed_user(&pool, event_id, "Sweeper").await;
+
+    for status in ["done", "failed", "processing", "pending"] {
+        let live = seed_aged_upload(
+            &pool,
+            event_id,
+            user_id,
+            status,
+            None,
+            "originals/e/live.jpg",
+            true,
+        )
+        .await;
+        assert!(
+            !sweep_selects(&pool, FAILED_DAYS, DELETED_HOURS)
+                .await
+                .contains(&live),
+            "a non-deleted upload with status {status} must never be swept"
+        );
+    }
+}
+
+/// THE FIX. An upload a guest or host deliberately deleted is reclaimed once past 24 hours.
+///
+/// PREVENTS: the regression back to a sweep scoped to `compression_status = 'failed'`, which is
+/// what let the quota stop bounding the disk. This assertion is the inverse of the one this file
+/// used to make.
+#[sqlx::test]
+async fn a_deliberately_deleted_upload_is_reclaimed_after_a_day(pool: PgPool) {
+    let event_id = seed_event(&pool, "sweep-deleted").await;
+    let user_id = seed_user(&pool, event_id, "Curator").await;
+
+    let deleted = seed_aged_upload(
+        &pool,
+        event_id,
+        user_id,
+        "done",
+        Some(48),
+        "originals/e/owner.jpg",
+        true,
+    )
+    .await;
+    // Still inside the window — a mis-tap is recoverable for a day.
+    let recent = seed_aged_upload(
+        &pool,
+        event_id,
+        user_id,
+        "done",
+        Some(2),
+        "originals/e/recent.jpg",
+        true,
+    )
+    .await;
+
+    let selected = sweep_selects(&pool, FAILED_DAYS, DELETED_HOURS).await;
+    assert!(
+        selected.contains(&deleted),
+        "a deliberate delete past the window must be reclaimed — this is the leak"
+    );
+    assert!(
+        !selected.contains(&recent),
+        "a delete inside the window keeps its recovery grace"
+    );
+}
+
+/// The two windows are independent: a failure is retained far longer than a deliberate delete.
+///
+/// PREVENTS: collapsing them into one. Applying 24h to failures would destroy the recovery window
+/// the retained-original fix exists to provide; applying 14 days to deliberate deletes would mean
+/// nothing is ever reclaimed during an event.
+#[sqlx::test]
+async fn the_two_retention_windows_do_not_bleed_into_each_other(pool: PgPool) {
+    let event_id = seed_event(&pool, "sweep-windows").await;
+    let user_id = seed_user(&pool, event_id, "Windows").await;
+
+    // 48h old: past the deliberate window, nowhere near the failure window.
+    let failed_recent = seed_aged_upload(
+        &pool,
+        event_id,
+        user_id,
+        "failed",
+        Some(48),
+        "originals/e/f-recent.jpg",
+        false,
+    )
+    .await;
+    let deleted_same_age = seed_aged_upload(
+        &pool,
+        event_id,
+        user_id,
+        "done",
+        Some(48),
+        "originals/e/d-same.jpg",
+        false,
+    )
+    .await;
+    // 30 days old: past both.
+    let failed_old = seed_aged_upload(
+        &pool,
+        event_id,
+        user_id,
+        "failed",
+        Some(30 * 24),
+        "originals/e/f-old.jpg",
+        false,
+    )
+    .await;
+
+    let selected = sweep_selects(&pool, FAILED_DAYS, DELETED_HOURS).await;
+    assert!(
+        !selected.contains(&failed_recent),
+        "a 2-day-old compression failure is still inside its 14-day recovery window"
+    );
+    assert!(
+        selected.contains(&deleted_same_age),
+        "a deliberate delete of the same age is past its 24-hour window"
+    );
+    assert!(
+        selected.contains(&failed_old),
+        "a 30-day-old failure is past both windows"
+    );
+}
+
+/// Boundary behaviour on both windows.
+#[sqlx::test]
+async fn retention_windows_are_honoured_at_the_boundary(pool: PgPool) {
+    let event_id = seed_event(&pool, "sweep-boundary").await;
+    let user_id = seed_user(&pool, event_id, "Boundary").await;
+
+    let cases = [
+        ("failed", 13 * 24, false, "13 days"),
+        ("failed", 15 * 24, true, "15 days"),
+        ("done", 23, false, "23 hours"),
+        ("done", 25, true, "25 hours"),
+    ];
+    for (status, hours, expected, label) in cases {
+        let id = seed_aged_upload(
+            &pool,
+            event_id,
+            user_id,
+            status,
+            Some(hours),
+            "originals/e/b.jpg",
+            false,
+        )
+        .await;
+        assert_eq!(
+            sweep_selects(&pool, FAILED_DAYS, DELETED_HOURS)
+                .await
+                .contains(&id),
+            expected,
+            "a {status} upload deleted {label} ago: expected swept={expected}"
+        );
+        sqlx::query("DELETE FROM upload WHERE id = $1")
+            .bind(id)
+            .execute(&pool)
+            .await
+            .expect("clean up");
+    }
+}
+
+/// A row is re-selected until EVERY one of its paths is cleared.
+///
+/// PREVENTS: two failures at once. The sweep used to clear `original_path` alone, which was right
+/// for its only case (a failed compression produces no derivatives) but leaves preview, display and
+/// thumbnail on disk the moment it reaches a successfully processed upload — three files per
+/// upload, none of them counted in `original_size_bytes`, that nothing else ever removes. And a row
+/// whose paths are all cleared must stop coming back, or every hourly tick logs a phantom reclaim
+/// forever.
+#[sqlx::test]
+async fn a_row_is_reselected_until_every_path_is_cleared(pool: PgPool) {
+    let event_id = seed_event(&pool, "sweep-idempotent").await;
+    let user_id = seed_user(&pool, event_id, "Idem").await;
+    let id = seed_aged_upload(
+        &pool,
+        event_id,
+        user_id,
+        "done",
+        Some(48),
+        "originals/e/once.jpg",
+        true,
+    )
+    .await;
+
+    assert_eq!(sweep_selects(&pool, FAILED_DAYS, DELETED_HOURS).await, [id]);
+
+    // Clearing only the original is NOT enough — the derivatives are still on disk.
+    sqlx::query("UPDATE upload SET original_path = '' WHERE id = $1")
+        .bind(id)
+        .execute(&pool)
+        .await
+        .expect("clear original");
+    assert_eq!(
+        sweep_selects(&pool, FAILED_DAYS, DELETED_HOURS).await,
+        [id],
+        "derivatives left behind must keep the row selected"
+    );
+
+    sqlx::query(
+        "UPDATE upload SET preview_path = NULL, display_path = NULL, thumbnail_path = NULL
+         WHERE id = $1",
+    )
+    .bind(id)
+    .execute(&pool)
+    .await
+    .expect("clear derivatives");
+    assert!(
+        sweep_selects(&pool, FAILED_DAYS, DELETED_HOURS)
+            .await
+            .is_empty(),
+        "a fully swept row must not come back"
+    );
+}
+
+/// The derivative backfill must never resurrect what the sweep just reclaimed.
+///
+/// PREVENTS: an interaction, not a bug in either piece. The sweep nulls `preview_path`, and
+/// `backfill_stale_derivatives` selects on `display_path IS NULL AND preview_path IS NOT NULL` —
+/// close enough that a future edit to either could have the backfill re-decode an original that is
+/// no longer on disk, on every boot. `deleted_at IS NULL` is what keeps them apart.
+#[sqlx::test]
+async fn the_backfill_ignores_swept_rows(pool: PgPool) {
+    let event_id = seed_event(&pool, "sweep-backfill").await;
+    let user_id = seed_user(&pool, event_id, "Backfill").await;
+    seed_aged_upload(
+        &pool,
+        event_id,
+        user_id,
+        "done",
+        Some(48),
+        "originals/e/gone.jpg",
+        true,
+    )
+    .await;
+
+    // SRC: `services/compression.rs::backfill_stale_derivatives` — the selection, verbatim.
+    let backfilled: Vec<(Uuid, String, String)> = sqlx::query_as(
+        "SELECT id, original_path, mime_type FROM upload
+             WHERE deleted_at IS NULL AND mime_type LIKE 'image/%'
+               AND original_path IS NOT NULL
+               AND (
+                     (display_path IS NULL AND preview_path IS NOT NULL)
+                  OR derivatives_rev < $1
+               )",
+    )
+    .bind(1i16)
+    .fetch_all(&pool)
+    .await
+    .expect("backfill query");
+
+    assert!(
+        backfilled.is_empty(),
+        "a soft-deleted row must be invisible to the backfill, before or after sweeping"
+    );
+}

backend/tests/upload_concurrency.rs

@@ -0,0 +1,297 @@
+//! DB-backed integration tests for the two concurrency guards in the upload commit path
+//! (`handlers/upload.rs`). Both are SQL — a `FOR SHARE` row lock and an atomic compare-and-increment
+//! — and both are load-bearing for things a user can actually lose: a wedding photo, or the disk.
+//!
+//! `#[sqlx::test]` gives each test a fresh database with the real migrations applied.
+
+mod common;
+
+use std::sync::Arc;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::time::Duration;
+
+use chrono::{DateTime, Utc};
+use common::*;
+use sqlx::PgPool;
+use uuid::Uuid;
+
+/// SRC: `handlers/upload.rs:313-322` — the guarded quota increment, verbatim.
+/// Returns `rows_affected()`; the handler aborts the whole upload tx when this is 0.
+async fn quota_inc(exec: impl sqlx::PgExecutor<'_>, user_id: Uuid, size: i64, limit: i64) -> u64 {
+    sqlx::query(
+        "UPDATE \"user\" SET total_upload_bytes = total_upload_bytes + $2
+         WHERE id = $1 AND total_upload_bytes + $2 <= $3",
+    )
+    .bind(user_id)
+    .bind(size)
+    .bind(limit)
+    .execute(exec)
+    .await
+    .expect("quota_inc")
+    .rows_affected()
+}
+
+async fn total_bytes(pool: &PgPool, user_id: Uuid) -> i64 {
+    sqlx::query_scalar("SELECT total_upload_bytes FROM \"user\" WHERE id = $1")
+        .bind(user_id)
+        .fetch_one(pool)
+        .await
+        .expect("total_bytes")
+}
+
+// ─────────────────────────────────────────────────────────────────────────────
+// 5. The atomic quota increment
+// ─────────────────────────────────────────────────────────────────────────────
+
+/// Two attempts sized off ONE stale snapshot, each of which "fits" on its own, cannot both commit.
+/// The predicate re-reads `total_upload_bytes` inside the UPDATE, so the second matches 0 rows.
+///
+/// PREVENTS: one guest filling the disk. The handler's pre-flight quota check runs BEFORE the body is
+/// streamed — minutes earlier, for a 500 MB video. If the commit trusted that snapshot, a guest could
+/// start N uploads that each individually fit under the limit and land all N, blowing straight through
+/// the quota and (in a 1 GB container) taking the event down for everyone.
+#[sqlx::test]
+async fn quota_two_attempts_from_one_stale_snapshot_cannot_both_commit(pool: PgPool) {
+    let event_id = seed_event(&pool, "wedding").await;
+    let user_id = seed_user(&pool, event_id, "Gierige Gudrun").await;
+
+    const LIMIT: i64 = 100;
+    const SIZE: i64 = 60;
+
+    // THE STALE SNAPSHOT: the pre-flight check both uploads were admitted on.
+    let snapshot = total_bytes(&pool, user_id).await;
+    assert_eq!(snapshot, 0);
+    // Each upload, judged against that snapshot alone, fits: 0 + 60 <= 100. Twice.
+    assert!(snapshot + SIZE <= LIMIT);
+
+    assert_eq!(
+        quota_inc(&pool, user_id, SIZE, LIMIT).await,
+        1,
+        "the first upload commits"
+    );
+    assert_eq!(
+        quota_inc(&pool, user_id, SIZE, LIMIT).await,
+        0,
+        "the second MUST affect 0 rows — it was admitted on a snapshot that is now a lie \
+         (60 + 60 = 120 > 100). rows_affected() == 0 is what makes the handler abort."
+    );
+
+    assert_eq!(
+        total_bytes(&pool, user_id).await,
+        SIZE,
+        "never 120 — the quota held"
+    );
+}
+
+/// The same, but genuinely CONCURRENT: two transactions that both read `total = 0`, then both try to
+/// commit 60 bytes against a 100-byte limit. The second UPDATE blocks on the first's row lock and —
+/// because every predicate is on the ROW BEING UPDATED — Postgres re-evaluates it against the
+/// post-commit row (EPQ) rather than the statement's original snapshot. It matches nothing.
+///
+/// PREVENTS: exactly the same disk-filling overrun, on the path it actually happens — two uploads
+/// in flight at once, which is the normal case at a party.
+#[sqlx::test]
+async fn quota_guard_is_atomic_under_concurrent_transactions(pool: PgPool) {
+    let event_id = seed_event(&pool, "wedding").await;
+    let user_id = seed_user(&pool, event_id, "Gierige Gudrun").await;
+
+    const LIMIT: i64 = 100;
+    const SIZE: i64 = 60;
+
+    let mut tx1 = pool.begin().await.unwrap();
+    let mut tx2 = pool.begin().await.unwrap();
+
+    // Both transactions read the same snapshot and both would pass a naive `total + size <= limit`
+    // check done in Rust.
+    for tx in [&mut tx1, &mut tx2] {
+        let seen: i64 = sqlx::query_scalar("SELECT total_upload_bytes FROM \"user\" WHERE id = $1")
+            .bind(user_id)
+            .fetch_one(&mut **tx)
+            .await
+            .unwrap();
+        assert_eq!(seen, 0, "both see an empty quota");
+    }
+
+    // tx1 takes the row lock and commits.
+    assert_eq!(quota_inc(&mut *tx1, user_id, SIZE, LIMIT).await, 1);
+    tx1.commit().await.unwrap();
+
+    // tx2's UPDATE was written against the stale snapshot but is evaluated against the row as it
+    // now stands.
+    assert_eq!(
+        quota_inc(&mut *tx2, user_id, SIZE, LIMIT).await,
+        0,
+        "the loser MUST see 0 rows affected — this is the entire quota guarantee"
+    );
+    tx2.rollback().await.unwrap();
+
+    assert_eq!(total_bytes(&pool, user_id).await, SIZE);
+
+    // And an upload that legitimately fits in what's left still succeeds — the guard rejects
+    // overruns, not everything.
+    assert_eq!(
+        quota_inc(&pool, user_id, 40, LIMIT).await,
+        1,
+        "0 + 60 + 40 == 100, exactly at the limit"
+    );
+    assert_eq!(total_bytes(&pool, user_id).await, LIMIT);
+    assert_eq!(
+        quota_inc(&pool, user_id, 1, LIMIT).await,
+        0,
+        "and one byte more is refused"
+    );
+}
+
+// ─────────────────────────────────────────────────────────────────────────────
+// 6. The `FOR SHARE` upload lock vs. the release
+// ─────────────────────────────────────────────────────────────────────────────
+
+/// SRC: `handlers/upload.rs:297-303` — the in-transaction re-check under a row lock, verbatim.
+async fn lock_and_read_event(
+    tx: &mut sqlx::PgConnection,
+    event_id: Uuid,
+) -> (Option<DateTime<Utc>>, Option<DateTime<Utc>>) {
+    sqlx::query_as(
+        "SELECT uploads_locked_at, export_released_at FROM event WHERE id = $1 FOR SHARE",
+    )
+    .bind(event_id)
+    .fetch_one(tx)
+    .await
+    .expect("FOR SHARE re-check")
+}
+
+/// THE GUARD AGAINST SILENT, PERMANENT PHOTO LOSS.
+///
+/// An upload holding `FOR SHARE` on the event row must BLOCK the `UPDATE event SET
+/// export_released_at = NOW()` in `release_gallery` until it commits. Either the upload commits first
+/// — and the release (hence the export snapshot) is strictly ordered after it, so the keepsake
+/// CONTAINS the photo — or the release commits first and the upload observes the lock and rejects
+/// (reversibly: the client keeps the blob and resumes after a reopen).
+///
+/// PREVENTS: the lost wedding photo. Without this serialization: a guest starts a 500 MB video, the
+/// pre-flight lock check passes, the host releases the gallery, the export workers snapshot the
+/// uploads table, and THEN the upload commits. The photo appears in the live feed but is missing from
+/// the downloaded keepsake, forever — nothing ever regenerates it and nobody ever notices.
+#[sqlx::test]
+async fn for_share_upload_lock_serializes_against_release(pool: PgPool) {
+    let event_id = seed_event(&pool, "wedding").await;
+    let user_id = seed_user(&pool, event_id, "Fotograf Fritz").await;
+
+    // ── The guest's upload transaction takes the share lock. ──
+    let mut upload_tx = pool.begin().await.unwrap();
+    let (locked, released) = lock_and_read_event(&mut upload_tx, event_id).await;
+    assert!(
+        locked.is_none() && released.is_none(),
+        "uploads are open, so we proceed to commit"
+    );
+
+    // ── Concurrently, the host hits "Galerie freigeben". ──
+    let release_done = Arc::new(AtomicBool::new(false));
+    let release_task = {
+        let pool = pool.clone();
+        let release_done = release_done.clone();
+        tokio::spawn(async move {
+            sqlx::query(
+                "UPDATE event
+                 SET export_released_at = NOW(),
+                     uploads_locked_at  = COALESCE(uploads_locked_at, NOW()),
+                     export_epoch       = export_epoch + 1
+                 WHERE id = $1 AND export_released_at IS NULL",
+            )
+            .bind(event_id)
+            .execute(&pool)
+            .await
+            .expect("release");
+            release_done.store(true, Ordering::SeqCst);
+        })
+    };
+
+    // The release MUST be stuck behind our `FOR SHARE` row lock. (`FOR SHARE` conflicts with the
+    // `FOR UPDATE` lock the UPDATE needs, so Postgres makes it wait — this is not a timing race,
+    // it is a lock-conflict guarantee; the sleep only gives it every chance to wrongly proceed.)
+    tokio::time::sleep(Duration::from_millis(750)).await;
+    assert!(
+        !release_done.load(Ordering::SeqCst),
+        "the release MUST block while an upload holds FOR SHARE — if it can slip past, the export \
+         snapshot is taken while a photo is still committing and that photo is lost forever"
+    );
+
+    // The photo commits. It is now unambiguously part of the upload set.
+    let upload_id: Uuid = sqlx::query_scalar(
+        "INSERT INTO upload (event_id, user_id, original_path, mime_type, original_size_bytes)
+         VALUES ($1, $2, 'originals/wedding/x.jpg', 'image/jpeg', 1234) RETURNING id",
+    )
+    .bind(event_id)
+    .bind(user_id)
+    .fetch_one(&mut *upload_tx)
+    .await
+    .unwrap();
+    upload_tx.commit().await.unwrap();
+
+    // Only now can the release proceed.
+    tokio::time::timeout(Duration::from_secs(5), release_task)
+        .await
+        .expect("the release must unblock once the upload commits")
+        .unwrap();
+
+    // THE PAYOFF: the export snapshot — the very query the ZIP worker runs — sees the photo. Order
+    // enforced by the lock: upload commit < release < snapshot.
+    let snapshot: Vec<Uuid> = sqlx::query_scalar(
+        "SELECT u.id FROM upload u
+           JOIN \"user\" usr ON usr.id = u.user_id
+          WHERE u.event_id = $1 AND u.deleted_at IS NULL
+            AND usr.uploads_hidden = FALSE AND usr.is_banned = FALSE",
+    )
+    .bind(event_id)
+    .fetch_all(&pool)
+    .await
+    .unwrap();
+    assert_eq!(
+        snapshot,
+        vec![upload_id],
+        "the released keepsake CONTAINS the in-flight photo"
+    );
+}
+
+/// The other side of the same lock: once the release has COMMITTED, the next upload's `FOR SHARE`
+/// re-read sees `export_released_at` set and the handler rejects it with `UploadsLocked`.
+///
+/// PREVENTS: the same lost photo, on the losing side of the race — a photo committing AFTER the
+/// export snapshot would be in the live feed but missing from the keepsake. Rejecting is the correct
+/// outcome, and it is reversible: `UploadsLocked` (not Forbidden) tells the client to keep the blob
+/// and resume when the host reopens.
+#[sqlx::test]
+async fn upload_after_release_commits_sees_the_lock_and_is_rejected(pool: PgPool) {
+    let event_id = seed_event(&pool, "wedding").await;
+
+    // Before the release, the re-check passes.
+    let mut tx = pool.begin().await.unwrap();
+    let (locked, released) = lock_and_read_event(&mut tx, event_id).await;
+    assert!(locked.is_none() && released.is_none());
+    tx.rollback().await.unwrap();
+
+    assert_eq!(release_gallery(&pool, "wedding").await, Some(1));
+
+    // After it, the identical re-check sees the release and the handler bails out.
+    let mut tx = pool.begin().await.unwrap();
+    let (locked, released) = lock_and_read_event(&mut tx, event_id).await;
+    assert!(
+        released.is_some(),
+        "the FOR SHARE re-read MUST observe the committed release"
+    );
+    assert!(
+        locked.is_some(),
+        "release locks uploads in the same statement (release ⇒ lock)"
+    );
+    tx.rollback().await.unwrap();
+
+    // And a reopen makes it uploadable again — the rejection was reversible, not terminal.
+    assert_eq!(open_event(&pool, "wedding").await, 1);
+    let mut tx = pool.begin().await.unwrap();
+    let (locked, released) = lock_and_read_event(&mut tx, event_id).await;
+    assert!(
+        locked.is_none() && released.is_none(),
+        "the guest can resume their upload"
+    );
+    tx.rollback().await.unwrap();
+}

docker-compose.dev.yml

@@ -11,3 +11,31 @@ services:
     # is tolerated (warned) rather than rejected.
     environment:
       APP_ENV: development
+      # `.env` sets DATABASE_URL to @localhost for the run-backend-natively workflow
+      # (the db port is published above for that). When the app runs IN a container,
+      # localhost is the app itself — point it at the `db` service instead. Creds are
+      # interpolated from .env so nothing is hardcoded.
+      DATABASE_URL: postgres://${POSTGRES_USER}:${POSTGRES_PASSWORD}@db:5432/${POSTGRES_DB}
+      # `.env` sets MEDIA_PATH to a HOST path (/home/fabi/EventSnap/media) for the
+      # run-backend-natively workflow. In a container that path doesn't exist and the
+      # app user can't create it from `/`, so every upload 500s with EACCES. The media
+      # volume is mounted at /media (see docker-compose.yml) — point the app there.
+      MEDIA_PATH: /media
+      # Recent Docker Compose interpolates env_file values, so the `$` segments of the
+      # bcrypt ADMIN_PASSWORD_HASH in .env get eaten (the salt reads as an unset var) —
+      # every admin login then 401s. Re-supply it here with `$` doubled to `$$` so Compose
+      # passes the literal hash. NOTE: production (docker-compose.yml + .env) has the SAME
+      # bug — escape the hash as `$$` in .env, or set it via `environment:` there too.
+      ADMIN_PASSWORD_HASH: "$$2b$$12$$PAteqCNpsbm6d0HTJcywfOaUovjAU.iNVlsL7EDYaRC/z4P/xv7ye"
+      # Smoke-testing the comment kill-switch: boot-time flag, so it needs a restart
+      # (not an admin-UI toggle). Backend rejects new comments (403) and the frontend
+      # hides the whole comment UI. Flip back to true (or drop this line) to restore.
+      COMMENTS_ENABLED: "false"
+
+  caddy:
+    # The prod caddy service has no env_file, so the Caddyfile's `{$DOMAIN}` expands
+    # to empty and the site block collapses into a malformed global block. Supply it
+    # for local dev (from .env → localhost, which Caddy serves with a local self-signed
+    # cert). NOTE: the prod compose likely needs DOMAIN wired to caddy too.
+    environment:
+      DOMAIN: ${DOMAIN}

docker-compose.yml

@@ -1,7 +1,20 @@
+# Docker's default json-file driver is UNBOUNDED. Those files land on the HOST
+# filesystem, outside every `deploy.resources.limits` below — so the container memory
+# caps do nothing to stop them. On a single-box deployment the host disk is also where
+# the postgres_data and media_data volumes live, and a full disk stops Postgres writing
+# WAL, which takes the whole event down. 4 services x 3 x 10m caps the worst case at
+# ~120 MiB. Applied to every service via the anchor; a new service must opt in too.
+x-logging: &default-logging
+  driver: json-file
+  options:
+    max-size: "10m"
+    max-file: "3"
+
 services:
   db:
     image: postgres:16-alpine
     restart: unless-stopped
+    logging: *default-logging
     env_file: .env
     environment:
       POSTGRES_USER: ${POSTGRES_USER}
@@ -17,18 +30,37 @@ services:
     deploy:
       resources:
         limits:
-          memory: 512M
+          # 1G, not 512M. DATABASE_MAX_CONNECTIONS defaults to 30 for a ~100-guest event
+          # (feed polling + SSE + uploads at once), and 30 backends plus Postgres 16's
+          # default shared_buffers leaves very little headroom at 512M. An OOM here does
+          # not degrade one feature — it takes the event down, because every request
+          # path touches the database. Memory is the cheaper knob than shrinking the
+          # pool back and reintroducing the queueing it was raised to fix.
+          #
+          # Raising DATABASE_MAX_CONNECTIONS further means raising this too.
+          memory: 1G
 
   app:
     build:
       context: ./backend
       dockerfile: Dockerfile
     restart: unless-stopped
+    logging: *default-logging
     env_file: .env
     environment:
+      # Default to info. The code fallback in main.rs is info too, but a stock deploy
+      # sets RUST_LOG nowhere, and this is the layer an operator will actually find when
+      # they need to raise it for a single event ("RUST_LOG=eventsnap_backend=debug").
+      RUST_LOG: ${RUST_LOG:-info}
       # Activates the production secret guard in config.rs — refuses to boot with
       # placeholder JWT_SECRET / ADMIN_PASSWORD_HASH.
       APP_ENV: production
+      # The media volume is mounted at /media (below), so the app MUST write there.
+      # Pin it here rather than trusting .env: if MEDIA_PATH in .env points elsewhere
+      # (e.g. a host path used for running the backend natively) the container can't
+      # create it and every upload 500s with EACCES. `environment` overrides `env_file`,
+      # so this is authoritative for the container.
+      MEDIA_PATH: /media
     depends_on:
       db:
         condition: service_healthy
@@ -40,7 +72,11 @@ services:
     expose:
       - "3000"
     healthcheck:
-      test: ["CMD-SHELL", "wget -q -O- http://localhost:3000/health || exit 1"]
+      # Use 127.0.0.1, NOT localhost: the app binds IPv4 (0.0.0.0) but `localhost`
+      # resolves to ::1 (IPv6) first inside the container, so a localhost probe gets
+      # "connection refused" and the container never turns healthy — which would leave
+      # Caddy (gated on `condition: service_healthy` below) blocked forever on boot.
+      test: ["CMD-SHELL", "wget -q -O- http://127.0.0.1:3000/health || exit 1"]
       interval: 10s
       timeout: 5s
       retries: 5
@@ -57,6 +93,7 @@ services:
       context: ./frontend
       dockerfile: Dockerfile
     restart: unless-stopped
+    logging: *default-logging
     env_file: .env
     environment:
       # adapter-node behind Caddy TLS needs the public origin for CSRF checks on
@@ -67,7 +104,9 @@ services:
     expose:
       - "3001"
     healthcheck:
-      test: ["CMD-SHELL", "wget -q -O- http://localhost:3001/ >/dev/null 2>&1 || exit 1"]
+      # 127.0.0.1, not localhost — see the app healthcheck note above (IPv4 bind vs
+      # ::1 resolution would leave this container permanently unhealthy).
+      test: ["CMD-SHELL", "wget -q -O- http://127.0.0.1:3001/ >/dev/null 2>&1 || exit 1"]
       interval: 10s
       timeout: 5s
       retries: 5
@@ -80,6 +119,13 @@ services:
   caddy:
     image: caddy:2-alpine
     restart: unless-stopped
+    logging: *default-logging
+    environment:
+      # The Caddyfile's site address is `{$DOMAIN}`, read from THIS container's env.
+      # Without it, `{$DOMAIN}` expands to empty, the site block collapses, and Caddy
+      # serves nothing / fails to obtain a TLS cert. `env_file` alone wouldn't help —
+      # Caddy needs it in `environment`, and this keeps the Caddyfile the single source.
+      DOMAIN: ${DOMAIN}
     ports:
       - "80:80"
       - "443:443"

docs/USER_JOURNEYS.md

@@ -129,18 +129,23 @@ the Host can clean up later).
    viewer). Progress is visible in the Admin dashboard's Export tab; SSE
    `export-progress` keeps it live; `export-available` notifies all guests when ready.
 5. **Nutzerverwaltung** — search users; per-user controls:
-   - **Sperren** opens a confirmation modal with a checkbox "Uploads aus der Galerie
-     ausblenden" — Host chooses whether to hide the user's existing uploads or leave them
-     visible. Submitting calls `POST /host/users/{id}/ban` with `hide_uploads`.
-   - **Entsperren** lifts the ban.
-   - **Host** promotes a guest to host.
-   - **Degradieren** — visible on Host rows. A Host can demote *other* Hosts back to
-     guest (planned). The button is hidden on the Host's own row to prevent self-lockout;
-     only an Admin can demote themselves out of moderation. Admins see Degradieren on
-     every Host row.
-   - **PIN zurücksetzen** (planned) — generates a new PIN and shows it once in a modal.
-     See journey §4. Hosts see this on Guest rows only; Admins see it on Guest + Host
-     rows.
+   - **Sperren** opens a confirmation modal. Banning **always hides** the user's existing
+     uploads (a banned user's content is "gone" everywhere) — there is no opt-out. Submitting
+     calls `POST /host/users/{id}/ban` (no body).
+   - **Entsperren** lifts the ban. Same authority boundary as ban (below): a plain Host may
+     only unban Guests; only an Admin may unban a Host.
+   - **Host** promotes a guest to host (Hosts and Admins may do this).
+   - **Degradieren** — demote a Host back to guest. **Only an Admin may change a Host's
+     role.** A plain Host may *not* demote a peer Host: doing so would let them then ban or
+     PIN-reset (→ `/recover` account-takeover) that ex-peer, since those guards key off the
+     target's *current* role. So the backend rejects it (403) and the button is hidden for
+     non-admin Hosts. Nobody may change their own role (self-lockout / self-escalation guard),
+     and Admins are un-demotable and un-bannable by anyone. (This tightens an earlier
+     "Hosts may demote other Hosts" design — see the F1 security fix.)
+   - **Sperren / PIN zurücksetzen** — a plain Host may act on Guests only; an Admin may act on
+     Guests + Hosts; nobody may act on an Admin. The buttons are hidden where they'd 403.
+     PIN reset generates a new PIN, shows it once in a modal, and revokes the target's
+     existing sessions (forcing re-auth with the new PIN). See journey §4.
 6. **Deleting content** — Host can delete any upload or comment via the moderation routes
    (`DELETE /host/upload/{id}`, `DELETE /host/comment/{id}`). On mobile this is also
    reachable by long-pressing the content (planned, see §15).
@@ -154,11 +159,19 @@ the Host can clean up later).
    ("Du bist gesperrt."). Ban enforcement lives on the write handlers and the
    host/admin extractors, not the base auth extractor.
 3. They can still browse the read-only feed (and download the export once it's released).
+   Their sessions are **not** revoked — this is a read-only ban, not a logout. Their own
+   live SSE stream is dropped by the `is_banned` revalidation (no live pushes), but plain
+   feed reads still work.
 4. They cannot upload, like, or comment; a banned host also loses all host/admin
    actions (including unbanning themselves).
-5. If `hide_uploads` was set on the ban, their existing uploads are filtered out of the
-   feed for everyone (`v_feed` enforces this), and a live `user-hidden` SSE event evicts
-   their cards from every open feed + the diashow without a reload.
+5. Banning **always hides**: the user's existing uploads are filtered out of the feed for
+   everyone (`v_feed`, `find_visible_media`, and the export query all enforce
+   `is_banned = FALSE`), and a live `user-hidden` SSE event evicts their cards from every
+   open feed + the diashow without a reload. A client that was offline/disconnected during
+   the live event doesn't miss the eviction: `uploads_hidden_at` is stamped at ban time
+   (migration 013) and the reconnect delta (`GET /feed/delta`) returns the banned users in
+   `hidden_user_ids`, so the feed and diashow replay the eviction on the next reconnect —
+   the projector-missed-the-live-push case is exactly why this exists.
 
 ## 11. Admin — instance configuration
 
@@ -180,7 +193,18 @@ the Host can clean up later).
 ## 12. Releasing the export and downloading
 
 1. Host (or Admin) taps **Galerie freigeben** in the dashboard.
-2. Server sets `event.export_released_at` and enqueues two background jobs.
+2. Server sets `event.export_released_at`, locks uploads, **bumps `event.export_epoch`**, and
+   enqueues two background jobs — all in ONE transaction (workers spawn after it commits, so a
+   client disconnecting mid-request can never leave the event released with no export to build).
+
+   The **epoch** is the whole generation model (migration 014). It is bumped in the same UPDATE as
+   any change to `export_released_at` — release and reopen are its only writers — and each
+   `export_job` row carries a copy of the epoch it was enqueued for. An export is downloadable
+   **iff** `released AND job.epoch = event.export_epoch AND job.status = 'done'`. Readiness is
+   therefore *derived*, never stored: it cannot drift, and a worker whose epoch has been retired
+   (by a reopen, a re-release, or a takedown) is inert — anything it writes is simply invisible.
+   A reopen retires the current keepsake instantly, which is why a reopened event serves no export
+   until the host releases again.
 3. ZIP job: streams `Gallery.zip` (`Photos/` + `Videos/`, full-quality originals) directly
    to disk via `async-zip`. Progress updates via `export-progress` SSE.
 4. HTML-viewer job: copies the pre-built viewer assets from
@@ -188,6 +212,11 @@ the Host can clean up later).
    `include_dir!`), generates `data.json` from the database, processes `_thumb`/`_full`
    variants for each upload, and assembles `Memories.zip`.
 5. Both jobs complete → server broadcasts `export-available` SSE.
+   **Takedowns:** if a host deletes an upload (or a comment) while the gallery is released, the
+   epoch is bumped and the keepsake is REGENERATED without it. Otherwise a photo removed on request
+   would live on forever in the already-generated archive — the one place it most needs to be gone.
+   The download 404s for the few seconds it takes to rebuild, which is the correct answer: serving
+   the old archive would serve the deleted photo.
 6. Any user opens `/export`:
    - Before release: friendly "Export not yet available" banner.
    - During generation: progress bars per artifact.

e2e/.prettierignore

@@ -0,0 +1,4 @@
+node_modules/
+playwright-report/
+test-results/
+package-lock.json

e2e/.prettierrc

@@ -0,0 +1,7 @@
+{
+  "useTabs": false,
+  "tabWidth": 2,
+  "singleQuote": true,
+  "trailingComma": "es5",
+  "printWidth": 100
+}