fix(deploy): a permanent upload outage, a dead-on-arrival Caddy, and 11pm commands that don't run

* Caddy had no read_body, on the reasoning that "a slow body still has to
  actually send bytes". That is an argument about disk, and disk is not the
  scarce resource: upload_admission budgets concurrent bodies at 4096 MiB and
  reserves the DECLARED cap, so a video/* upload reserves 500 MiB. Eight
  connections that stall mid-body hold the whole budget, every other guest
  waits 20s and gets a 503, and it never recovers on its own — the permit is
  held until the handler returns. No attacker needed: eight guests starting
  real videos and walking out of AP range does it, and TCP will not reap
  those sockets for hours. 30m carries a 500 MB upload at ~2.2 Mbit/s, so it
  does not fail the uploads this product exists to collect.

* APP_PORT is presented in .env.example as an ordinary editable line, while
  the healthcheck hardcodes 127.0.0.1:3000 and the Caddyfile hardcodes
  app:3000. Change it and the app boots and serves happily on the new port,
  the healthcheck fails forever, app never turns healthy — and because caddy
  is gated on service_healthy, CADDY NEVER STARTS. Port 443 dead for the
  whole event, sole diagnostic "dependency failed to start". Pinned in
  compose beside MEDIA_PATH and EXPORT_PATH, which are there for this reason.

* Runbook §12's recovery commands do not run as written: unwrapped
  "$POSTGRES_USER" is expanded by the operator's shell, which does not have
  it, so psql answers `FATAL: role "" does not exist`. §9 documents that trap
  two hundred lines earlier and wraps its own calls in sh -c; §12 did not.
  This is the block you run with the app crash-looping behind a live Caddy.
  Its DELETE also hard-coded versions 21,22,23 as if to be copied verbatim,
  on a tree that now has 31 migrations — now explicitly an example, with the
  instruction to take the numbers from the actual boot error.

* Migration counts corrected across the runbook and .env.example (22 -> 31,
  commit count 154 -> 196). All four were presented as literal command output
  the operator is invited to reproduce.

.env.example

@@ -19,7 +19,7 @@ DOMAIN=my-event.example.com
 # Copying this file and starting the stack without that step fails with `manifest unknown`.
 #
 # Do NOT "fix" this by dropping back to v0.12.0: no image was ever built for it, and a
-# 6-migration tree booting against a 22-migration database returns VersionMissing and
+# 6-migration tree booting against a 31-migration database returns VersionMissing and
 # crash-loops forever behind a live Caddy. §9 covers this in full.
 EVENTSNAP_VERSION=v0.13.0
 

Caddyfile

@@ -10,10 +10,19 @@
 			#
 			# read_header is tight: a legitimate client sends its headers in one go.
 			read_header 10s
-			# read_body is NOT set, and idle is generous: a guest pushing a 500 MB video over
-			# cellular legitimately takes many minutes, and a body timeout would fail exactly the
-			# uploads this product exists to collect. The header timeout is what stops the cheap
-			# attack; a slow *body* still has to actually send bytes.
+			# read_body is GENEROUS but present. It was omitted on the reasoning that "a slow body
+			# still has to actually send bytes" — which is an argument about disk, and disk is not
+			# the scarce resource here. `upload_admission` budgets concurrent bodies at 4096 MiB and
+			# reserves the DECLARED cap, so a `video/*` upload reserves 500 MiB: eight connections
+			# that stall mid-body hold the entire budget, every other guest waits 20s and gets a
+			# 503, and it never recovers on its own because the permit is held until the handler
+			# returns. That needs no attacker — eight guests starting real videos and then walking
+			# out of AP range does it, and TCP will not reap those sockets for hours.
+			#
+			# 30m carries a 500 MB video at ~2.2 Mbit/s sustained, which is well under venue wifi
+			# and under most cellular, so it does not fail the uploads this product exists to
+			# collect. It does bound the leak to something that drains.
+			read_body 30m
 			idle 5m
 		}
 	}

DEPLOYMENT_RUNBOOK.md

@@ -537,9 +537,9 @@ explanation:
 
 ```
 $ git ls-tree --name-only v0.12.0 backend/migrations/ | wc -l
-12          # 6 migrations. HEAD has 22.
+12          # 6 migrations. HEAD has 31.
 $ git rev-list --count v0.12.0..HEAD
-154
+196
 ```
 
 `db.rs` runs `sqlx::migrate!()` with no `set_ignore_missing`, so an image built from a 6-migration
@@ -591,7 +591,7 @@ covers both. It exists so that the rollback line in the emergency card is safe t
 catastrophic. **If you genuinely need to undo a code change during the event, you cannot; freeze
 early enough that you never have to.**
 
-**Across a migration boundary — avoid by freezing.** If you must: all 22 migrations have paired
+**Across a migration boundary — avoid by freezing.** If you must: all 31 migrations have paired
 `.down.sql` files, but **none of them removes its own `_sqlx_migrations` row**, so that second step
 is mandatory and undocumented:
 
@@ -799,23 +799,29 @@ differently, the next boot aborts with *"migration 21 was previously applied but
 modified"*, `main` exits non-zero, and `restart: unless-stopped` makes it **permanent** — with
 Caddy still routing traffic to the dead container.
 
-Main-line `021`–`023` are byte-identical to what shipped, so a box that only ever ran tagged
+Every main-line migration is byte-identical to what shipped, so a box that only ever ran tagged
 releases is unaffected. **Verify rather than assume** — run this against the server before any
-deploy:
+deploy.
+
+Note the `sh -c` wrapping, for the same reason as §9: `POSTGRES_USER` and `POSTGRES_DB` live in
+`.env`, which Compose reads and **your shell does not**. Unwrapped, `-U "$POSTGRES_USER"` sends
+`-U ""` and psql answers `FATAL: role "" does not exist` — at 11pm, with the app crash-looping.
 
 ```bash
-docker compose exec -T db psql -U "$POSTGRES_USER" "$POSTGRES_DB" -c \
-  "SELECT version, description, success FROM _sqlx_migrations ORDER BY version;"
+docker compose exec -T db sh -c \
+  'psql -U "$POSTGRES_USER" -d "$POSTGRES_DB" -c "SELECT version, description, success FROM _sqlx_migrations ORDER BY version;"'
 ```
 
 If the app is already crash-looping on a renumbered migration, and **only** if you have confirmed
-the SQL in the new file is equivalent to what was actually applied:
+the SQL in the new file is equivalent to what was actually applied. Take the version numbers from
+the crash message and the query above — do **not** copy the ones below, which are an example:
 
 ```bash
 docker compose stop app
-docker compose exec -T db psql -U "$POSTGRES_USER" "$POSTGRES_DB" -c \
-  "DELETE FROM _sqlx_migrations WHERE version IN (21,22,23);"
-docker compose start app     # re-applies 021-023, then continues
+# Replace 21,22,23 with the versions the boot error actually named.
+docker compose exec -T db sh -c \
+  'psql -U "$POSTGRES_USER" -d "$POSTGRES_DB" -c "DELETE FROM _sqlx_migrations WHERE version IN (21,22,23);"'
+docker compose start app     # re-applies exactly those, then continues
 ```
 
 This re-runs those migrations. They must be idempotent (`IF NOT EXISTS` / `IF EXISTS`) or this

docker-compose.yml

@@ -104,6 +104,14 @@ services:
       # create it and every upload 500s with EACCES. `environment` overrides `env_file`,
       # so this is authoritative for the container.
       MEDIA_PATH: /media
+      # Third member of the MEDIA_PATH / EXPORT_PATH family, and the nastiest of the three because
+      # the app itself reports nothing wrong. The healthcheck below hardcodes 127.0.0.1:3000 and
+      # the Caddyfile hardcodes app:3000, while `.env.example` presents APP_PORT as an ordinary
+      # editable line. Change it there and the app boots and serves happily on the new port, the
+      # healthcheck fails forever, `app` never turns healthy — and because caddy is gated on
+      # `service_healthy`, CADDY NEVER STARTS AT ALL. Port 443 is dead for the whole event and the
+      # only diagnostic is `dependency failed to start`.
+      APP_PORT: "3000"
       # Pinned for the same reason as MEDIA_PATH: `environment` beats `env_file`, so this cannot
       # be lost by an operator who copies `.env.example` and edits only the secrets — which is
       # the likely path, and `.env.example` ships the generic default of `true`.