Deploy: production Docker stack for a single host (Synology/QNAP NAS)

Everything needed to run the app on an Intel NAS that is also doing other
jobs: one published port, no host networking, memory/CPU caps and log
rotation on every container, and all state in bind mounts under DATA_ROOT
so mail survives image updates, project deletion in the NAS UI, and full
reinstalls — and so Hyper Backup/HBS3 can actually see it.

- docker/Dockerfile.backend: multi-stage, non-root (uid 10001), tini for
  the <10s graceful lease release. Installs the four plugins as entry-point
  distributions. One image, several roles via docker/entrypoint.sh
  (api | worker-sync | worker-jobs | migrate | reindex | plugins).
- docker/Dockerfile.frontend + nginx.conf: SPA + /api reverse proxy with
  the WebSocket upgrade for /api/ws, and X-Forwarded-Proto preserved so
  the API still emits __Host-/Secure cookies when TLS is terminated by
  the NAS reverse proxy (identity/cookies.py keys off request scheme).
- docker/docker-compose.prod.yml: project name webmail-prod, NOT webmail —
  docker-compose.yml (dev services) owns that name, and two compose files
  sharing one project name fight over each other's containers.
  Meilisearch is an opt-in profile; SEARCH_BACKEND=pg is the default so a
  small NAS pays nothing for search.
- migrate runs as a one-shot (core Alembic head + every plugin branch)
  that everything else waits on, so a bad migration can never leave new
  code running against an old schema.
- docker/backup.sh: nightly pg_dump verified with `pg_restore --list`
  before it counts as a backup, with retention and a baseline on first
  start.
- deploy/webmail.sh: init/doctor/up/down/status/logs/update/rollback/
  backup/restore/reindex/psql/shell. `update` is backup -> images ->
  migrate -> roll workers, api, web -> health-gate, with automatic
  rollback to the previous version if the gate fails. `doctor` refuses to
  be quiet when DATA_ROOT is on NFS/SMB (silent Postgres corruption).
- deploy/build-push.sh: build images off-NAS (the frontend build wants
  ~2GB RAM) and push to Gitea, or --save a tar to carry over.
- scripts/reindex_search.py: rebuild the search index from Postgres alone.
  Every SearchDoc field is already stored, so the index is derived data
  that never needs backing up — this closes the only real objection to
  running Meilisearch on a box whose volumes may be wiped.
- pyproject: package-data for accounts/presets.yaml and the shared plugin
  Alembic env. Without it a non-editable install (i.e. any image) silently
  ships a package that fails at runtime.
- GET /api/version, used by the deploy health gate.

Verified end to end on a real stack: fresh install, all services healthy,
core + 4 plugin migration branches applied, login/SPA/plugin bundles
through nginx, WS upgrade returning 101, __Host- cookies under a
simulated TLS proxy, backup -> restore round-trip preserving user and
plugin schema, failed-update auto-rollback (both a bad migration and a
boot-crashing API), and Meilisearch profile serving a live query.
ruff + mypy --strict clean, 363/363 backend tests pass.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Nux3LCu4zP9nih4BRhPyHw

backend/app/config.py

@@ -32,6 +32,9 @@ class Settings(BaseSettings):
     session_ttl_days: int = Field(default=30, alias="SESSION_TTL_DAYS")
     max_attachment_mb: int = Field(default=25, alias="MAX_ATTACHMENT_MB")
     log_level: str = Field(default="INFO", alias="LOG_LEVEL")
+    # Release identifier baked into the container image at build time; surfaced
+    # by GET /api/version so a deploy can verify what is actually running.
+    app_version: str = Field(default="dev", alias="APP_VERSION")
 
     # --- Sync engine v2 (workers layer) --------------------------------------
     # Worker role: "sync" (lease-owned account runners) | "jobs" (arq consumer)