fix: gate uploads on keepsake headroom, and close five unattended-event gaps

The box is 2 vCPU / 4 GB / 40 GB, not the 4 vCPU / 8 GB / 80 GB that the audit,
the committed comments and README's sizing section all assumed. That correction
is what the first change is about; the rest are the remaining pre-event items.

THE ARCHIVE COULD BECOME UNBUILDABLE WHILE UPLOADS KEPT SUCCEEDING

`required_free_bytes` is `media × 1.1 × 2` — the ZIP and the HTML viewer are each
gallery-sized — and the export preflight also wants DISK_RESERVE_BYTES on top. The
upload gate, though, only refused below a FLAT 10 GB reserve. On 40 GB that let
uploads run to ~25 GB of media while a release needed `2.2 × 25 + 10` = 65 GB free.
Every upload in that band succeeded and the keepsake could then never be built: the
product's entire promise, failing silently at the end of the night with nobody there.

The gate now enforces the invariant that actually matters — never accept an upload
that would make the keepsake unbuildable — sharing `required_free_bytes` with the
preflight so the two cannot drift into disagreeing about the same question. Uploads
stop at ~8 GB of media on this disk, with a German message naming the cause.
Refusing the 1001st photo beats losing all 1000.

`media_total.rs` backs it: SUM(user.total_upload_bytes) over ~100 rows, cached 5s,
rather than `estimate_export_bytes`'s join across every upload. It counts hidden and
banned users' bytes, which the export excludes — skew in the SAFE direction, so the
gate closes marginally early rather than late. Fails open on a query error.

A test pins the gate against the preflight across the whole gallery-size range, and
a second asserts the per-user floor alone would over-commit the volume — i.e. that
the global gate is what must bind.

THE WATCHDOG ABORTED HEALTHY UPLOADS EVERY TIME A PHONE WAS POCKETED

`Date.now()` advances while a backgrounded phone is frozen but `setInterval` does
not, so the first tick after a screen lock read the whole sleep as silence and
aborted — re-sending a video from byte zero and burning one of five PERMANENT
auto-attempts. The interval is now its own suspension detector: a tick that arrives
125s late for a 5s schedule credits that window back, because a period the watchdog
could not observe is not evidence of silence.

Chosen over a `visibilitychange` listener, which only covers causes that fire that
event — a throttled-but-visible tab, a closed lid and an occluded window all freeze
timers without one — and which would have needed module state, an SSR guard and a
teardown for strictly less coverage. `performance.now()` was rejected because Safari
pauses it across system sleep on some paths and Chrome does not.

The credit buys one fresh window, not immunity: a socket iOS reaped while
backgrounded still aborts ~90s after resume rather than hanging for `xhr.timeout`
(5-60 min) with the queue's `processing` latch held.

Two latent leaks found while in there: `xhr.abort()` on a request already in
readyState DONE emits no `abort` event, so `settle()` never ran and the interval
re-aborted every 5s forever while `activeUploads` kept a stale entry (the ✕ button
silently stopped working); and a synchronous throw from `xhr.send` — a blob whose
backing store the OS purged — leaked the same way. Both closed.

OKLCH MADE THE DELETE BUTTON INVISIBLE ON SAMSUNG'S DEFAULT BROWSER

red/amber/green were never in the @theme block and fell through to Tailwind v4's
`oklch()` defaults, which Safari <15.4, Chrome <111 and Samsung Internet <22 cannot
parse: `var(--color-red-600)` is then invalid at computed-value time, `background-color`
falls back to transparent, and `.btn-danger` renders white text on nothing. Pinned to
Tailwind's own defaults gamut-mapped to sRGB by Lightning CSS — the converter already
in this pipeline — so modern browsers render exactly what they render today. Verified
against seven hex fallbacks it had already emitted for the /alpha forms. rose and teal
(avatar chips) had the same leak. The app CSS goes from 40 oklch declarations to 0.

Also fixes `--color-purple-950`, which was simply missing: `dark:bg-purple-950/50` on
the host dashboard was rendering default violet on EVERY browser, off-brand.

The keepsake viewer only picks this up on a rebuild, so its committed artefact is
rebuilt here too — still single-file, still zero external references.

A BRICKED BOOT LOOKED LIKE A SPINNER FOREVER

With `ssr = false` the page is empty until the bundle mounts, so a chunk 404 after a
redeploy or a dead uplink left the guest on the boot spinner with no message, no
reload control, and in a standalone PWA no URL bar. A 15s timeout in the existing
nonce'd IIFE (no CSP change) swaps in German copy and a reload button. Deliberately a
timeout rather than feature detection: a SyntaxError in the bundle is invisible to any
capability check. Plus a <noscript>, since there was nothing at all to see without JS.

EVERY 4xx WAS INVISIBLE AT ANY LOG LEVEL

tower_http counts 4xx as a success, so it logs at DEBUG while production runs at info.
If guests spend the evening hitting 429s or 413s, the post-event logs said nothing.
Now one WARN per client error; 5xx excluded because Internal already logs its source
chain and the pool-exhaustion 503 logs at construction.

A DEAD FRONTEND SERVED A BLANK 502

`handle_errors 5xx` with an inline German page (the caddy service mounts only the
Caddyfile, so there is no volume to ship a static file through). Verified empirically
against this config, not from documentation: an upstream 404 through `reverse_proxy`
still arrives as untouched `application/json`, and only a dial failure renders the
page. That mattered — the keepsake download navigates a hidden iframe and DEPENDS on a
real 404/429 arriving, and swallowing those would have been worse than the blank 502.

CONFIG CORRECTIONS FOR THE REAL HARDWARE

DATABASE_MAX_CONNECTIONS 30 → 15: sized to 2 vCPU rather than to the guest count.
Since migration 024 a feed page costs well under a millisecond, so connections are no
longer spent waiting, and 30 backends crowd the db container's 1 GB on a 4 GB host.
COMPRESSION_WORKER_CONCURRENCY stays at 2 — the merged heavy-image permit already
serialises anything over 150 MiB, so the "two 48 MP photos" worst case that number was
sized against is unreachable; dropping to 1 would halve light-path throughput and push
more feed tiles onto full-size originals. README's sizing section rewritten for the
actual disk.

Verified: 149/149 backend tests against a live Postgres, clippy clean, 57/57 vitest,
svelte-check 0 errors, eslint clean, vite build, export-viewer rebuild, caddy validate,
compose YAML parse.

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

frontend/src/lib/upload-queue.test.ts

@@ -3,7 +3,8 @@ import {
 	classifyUploadStatus,
 	isReversibleLock,
 	entryToQueueItem,
-	shouldAbortForStall
+	shouldAbortForStall,
+	suspendedSinceLastTick
 } from './upload-queue';
 
 /**
@@ -140,4 +141,55 @@ describe('shouldAbortForStall', () => {
 		expect(shouldAbortForStall(now - 91_000, now, true)).toBe(false);
 		expect(shouldAbortForStall(now - 121_000, now, true)).toBe(true);
 	});
+
+});
+
+/**
+ * The watchdog measures SILENCE via `Date.now()`, but a backgrounded phone freezes the
+ * interval while the clock keeps running. Without crediting the un-run window back, the first
+ * tick after a screen lock reads the whole sleep as a stall and aborts a healthy upload —
+ * re-sending from byte zero and spending one of five permanent auto-attempts. That is what
+ * every phone does between shots at a party.
+ *
+ * Detecting the freeze from the tick gap (rather than from `visibilitychange`) also covers the
+ * causes that fire no visibility event at all: a throttled-but-visible tab, a closed lid, an
+ * occluded window.
+ */
+describe('suspendedSinceLastTick', () => {
+	const now = 1_000_000;
+
+	it('credits nothing for a tick that arrived on schedule', () => {
+		expect(suspendedSinceLastTick(now - 5_000, now, 5_000)).toBe(0);
+	});
+
+	it('credits nothing for ordinary timer jitter or throttling', () => {
+		expect(suspendedSinceLastTick(now - 6_900, now, 5_000)).toBe(0);
+	});
+
+	it('credits the whole frozen window when the interval did not run', () => {
+		// Screen locked ~2 minutes: a 5s interval arriving 130s late.
+		expect(suspendedSinceLastTick(now - 130_000, now, 5_000)).toBe(125_000);
+	});
+
+	it('credits nothing when the clock jumps backwards (NTP correction)', () => {
+		expect(suspendedSinceLastTick(now + 60_000, now, 5_000)).toBe(0);
+	});
+
+	it('a suspension longer than the stall ceiling does not abort a healthy upload', () => {
+		// The bug, end to end: 3 minutes suspended, interval resumes, no bytes since.
+		const lastProgressAt = now - 180_000;
+		const credited = Math.min(
+			now,
+			lastProgressAt + suspendedSinceLastTick(now - 185_000, now, 5_000)
+		);
+		expect(shouldAbortForStall(credited, now, false)).toBe(false);
+	});
+
+	it('but a socket still silent 91s AFTER resume is aborted, never left to xhr.timeout', () => {
+		// iOS reaps backgrounded sockets without firing `error`. The credit buys one fresh
+		// window, not immunity — otherwise a dead upload would hang for 5-60 minutes holding
+		// the queue's `processing` latch.
+		const resumedAt = now - 91_000;
+		expect(shouldAbortForStall(resumedAt, now, false)).toBe(true);
+	});
 });

frontend/src/lib/upload-queue.ts

@@ -94,6 +94,45 @@ export function shouldAbortForStall(
 	return now - lastActivityAt > ceiling;
 }
 
+/**
+ * Normal timer jitter/throttling budget. A tick later than `interval + this` did not run
+ * because the page was suspended, not because it was merely late.
+ */
+const SUSPEND_TOLERANCE_MS = 2_000;
+
+/**
+ * Wall-clock the watchdog interval FAILED to cover because the page was suspended.
+ *
+ * `Date.now()` keeps advancing while a backgrounded phone is frozen, but `setInterval` does
+ * not run. So the first tick after a screen lock saw the entire sleep as "no bytes moved" and
+ * aborted a connection that was very possibly healthy — restarting a 200 MB video from byte
+ * zero, burning one of five PERMANENT auto-attempts (`chargeAttempt`), and breaking the drain
+ * loop for every other queued photo. A phone in a pocket between shots is the common case at a
+ * party, not an edge case.
+ *
+ * The interval is its own suspension detector: a tick scheduled 5s out that arrives 130s late
+ * means the page was frozen for ~125s, and that is exactly the window the watchdog had no
+ * right to measure. Deliberately chosen over a `visibilitychange` listener, which only covers
+ * the causes that happen to fire that event — a throttled-but-visible tab, a closed laptop lid
+ * and an occluded window all freeze timers without one. It also needs no listener, no
+ * module-level state, no SSR guard and no teardown.
+ *
+ * `performance.now()` was rejected as the clock source: Safari pauses it across system sleep
+ * on some paths while Chrome does not, which is precisely the non-uniformity that makes it
+ * unusable as the sole signal.
+ *
+ * Returns 0 for a normal tick, and 0 if the clock jumps BACKWARDS (an NTP correction) — that
+ * fails open, and the wall-clock `xhr.timeout` still bounds the request.
+ */
+export function suspendedSinceLastTick(
+	lastTickAt: number,
+	now: number,
+	intervalMs: number = STALL_CHECK_INTERVAL_MS
+): number {
+	const overshoot = now - lastTickAt - intervalMs;
+	return overshoot > SUSPEND_TOLERANCE_MS ? overshoot : 0;
+}
+
 /**
  * Wall-clock cap for one attempt, scaled by file size assuming a floor of ~8 kB/s — a
  * deliberately pessimistic rate, because killing a slow-but-progressing upload would lose
@@ -905,11 +944,25 @@ async function uploadItem(id: string): Promise<void> {
 			// connection that never errors and never completes. Only "no bytes moved" catches
 			// that without also punishing a healthy slow link.
 			let lastProgressAt = Date.now();
+			let lastTickAt = Date.now();
 			let bodySent = false;
 			let stalled = false;
 			const stallTimer = setInterval(() => {
-				if (!shouldAbortForStall(lastProgressAt, Date.now(), bodySent)) return;
+				// Never fire twice. `xhr.abort()` on a request already in `readyState === DONE`
+				// emits NO `abort` event, so `settle()` would never run: the interval would keep
+				// running forever, re-aborting every 5s, and `activeUploads` would keep a stale
+				// entry so the guest's ✕ button silently did nothing.
+				if (stalled) return;
+				const now = Date.now();
+				// Credit back the window the page was frozen. The watchdog measures SILENCE, and
+				// a period in which it could not observe anything is not evidence of silence.
+				// Clamped to `now` so a progress event delivered right at resume cannot push the
+				// timestamp into the future.
+				lastProgressAt = Math.min(now, lastProgressAt + suspendedSinceLastTick(lastTickAt, now));
+				lastTickAt = now;
+				if (!shouldAbortForStall(lastProgressAt, now, bodySent)) return;
 				stalled = true;
+				clearInterval(stallTimer);
 				xhr.abort();
 			}, STALL_CHECK_INTERVAL_MS);
 			const settle = (fn: () => void) => {
@@ -1018,7 +1071,16 @@ async function uploadItem(id: string): Promise<void> {
 					else reject(new NetworkError('Abgebrochen'));
 				})
 			);
-			xhr.send(formData);
+			// `send` can throw SYNCHRONOUSLY — most plausibly on a phone whose OS purged the
+			// backing store for the blob, leaving a neutered File. The executor would turn that
+			// into a rejection and `uploadItem` would recover, but `settle()` never runs: the
+			// stall interval leaks and `activeUploads` keeps a stale entry, so the ✕ button on
+			// that item stops working for the rest of the session.
+			try {
+				xhr.send(formData);
+			} catch {
+				settle(() => reject(new NetworkError('Netzwerkfehler')));
+			}
 		});
 
 		// Success — remove blob from IndexedDB, mark done