feat(deploy): dockerize web app for portainer git-stack deploy behind external traefik

Add root Dockerfile (standalone Next output, multi-stage pnpm build), drop
in-stack caddy in favor of publishing web's port for an external traefik
LXC (file-provider dynamic config included), and document the portainer
deploy flow.

Also fixes issues that blocked any production build: a bad auth-client
type cast, the ai SDK's mimeType->mediaType rename, an implicit-any
callback param, and push.ts eagerly calling webpush.setVapidDetails at
module import time (which crashed page-data collection whenever VAPID
env vars weren't present at build) — now lazily configured on first send.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docker/DEPLOY.md

@@ -0,0 +1,51 @@
+# Deploy: Portainer (git stack) + external Traefik LXC
+
+## Portainer
+
+1. Stacks → Add stack → **Repository**
+2. Repository URL: this repo. Reference: branch to track (e.g. `main`)
+3. Compose path: `docker/compose.prod.yml`
+4. Environment variables (Portainer stack env, not committed):
+
+```
+POSTGRES_DB=epicure
+POSTGRES_USER=epicure
+POSTGRES_PASSWORD=<generate>
+REDIS_PASSWORD=<generate>
+MINIO_ROOT_USER=<generate>
+MINIO_ROOT_PASSWORD=<generate>
+BETTER_AUTH_SECRET=<openssl rand -base64 32>
+BETTER_AUTH_URL=https://HOST_DOMAIN
+ENCRYPTION_SECRET=<openssl rand -base64 32>
+NEXT_PUBLIC_VAPID_PUBLIC_KEY=<npx web-push generate-vapid-keys>
+VAPID_PRIVATE_KEY=<from same command>
+WEB_PORT=3000
+# optional
+GOOGLE_CLIENT_ID=
+GOOGLE_CLIENT_SECRET=
+OPENROUTER_API_KEY=
+```
+
+5. Deploy the stack. Portainer builds `web` from the repo's root `Dockerfile` (see `build:` in compose.prod.yml) — no separate image push needed.
+6. Enable GitOps updates (webhook or polling) on the stack if you want redeploy-on-push.
+
+## First deploy: run migrations + seed
+
+Compose does not auto-migrate. After the stack is up, exec into the `web` container once (or run a one-off container against the same network) with `DATABASE_URL` set, then:
+
+```bash
+pnpm db:migrate
+pnpm db:seed   # tier definitions — first deploy only
+```
+
+## Traefik (separate LXC, file provider)
+
+1. Copy `docker/traefik/epicure.yml` into the traefik LXC's dynamic config directory.
+2. Replace `HOST_DOMAIN` with the public hostname and `PORTAINER_LXC_IP` with the portainer LXC's network IP (must match `WEB_PORT` published in compose.prod.yml).
+3. Confirm `certResolver` name matches what's set in traefik's static config.
+4. Traefik picks it up automatically (file provider watches for changes) — no restart needed.
+
+## Notes
+
+- `web` connects to `postgres`/`redis`/`minio` over the compose-internal network; only `web`'s port is published to the LXC host for traefik to reach.
+- `apps/web/next.config.ts` has `output: "standalone"` — required for the Dockerfile's slim runtime stage.