feat(container): M-Box 1-8 — stack-agnostic standalone Docker container

Shade now ships as a self-contained Docker image. Deploy one container
per project, any stack (Bun, Python, Go, Rust, Kotlin) can talk to it via
plain HTTP. Zero coupling to consumer codebases.

M-Box 1: Stale identity cleanup API
- touchIdentity + purgeStaleIdentities on PrekeyStore interface
- Implemented for Memory, SQLite, and Postgres backends
- SQLite adds last_activity_at column with migration ALTER for existing DBs
- Postgres adds the same via raw SQL with IF NOT EXISTS guards
- Routes call touchIdentity on register, bundle fetch, replenish
- 4 new tests for the cleanup API

M-Box 2: Stale cleanup background task
- StaleCleanupTask runs purge on startup + every 24h (configurable)
- Reads SHADE_STALE_DAYS (default 30) and SHADE_CLEANUP_INTERVAL_HOURS
- Wired into standalone.ts, stopped on graceful shutdown
- 5 new tests for the task

M-Box 3: Observer baked into the container
- standalone.ts conditionally mounts @shade/observer at /shade-observer
  when SHADE_OBSERVER_TOKEN is set (and >= 16 chars)
- Shared PrekeyServerEvents emitter feeds both routes and observer
- @shade/observer added as optional dependency of @shade/server

M-Box 4: Dockerfile with dashboard build
- Multi-stage build: oven/bun:1 builder → oven/bun:1-alpine runtime
- COPY packages/ wholesale so workspace lockfile resolves cleanly
- RUN bun run build inside shade-dashboard → dist/ → observer/dist/
- Non-root shade user, /data volume, healthcheck, env defaults
- Final image: 260 MB

M-Box 5: OpenAPI spec for stack-agnostic clients
- packages/shade-server/openapi.yaml documents all 9 endpoints with
  request/response schemas, security (Ed25519 signatures + bearer token)
- createOpenApiRoutes serves /openapi.yaml and /docs (Redoc viewer)
- Any language can generate a client with openapi-generator

M-Box 6: Docker CI pipeline
- .gitea/workflows/docker.yml builds + pushes on git tag v*
- scripts/build-docker.ts for local builds, supports --push with GITEA_TOKEN
- Root package.json: build:docker, publish:docker scripts

M-Box 7: Deployment documentation
- packages/shade-server/README rewritten: 5-line quickstart with the image
- docs/DEPLOYMENT.md: full reference, env vars, backup, Dokploy, PG setup
- examples/05-dokploy-deployment/docker-compose.yml updated to pull
  published image (gt.zyon.no/stian/shade-prekey:latest)
- Root README deployment section rewritten

M-Box 8: End-to-end verification
- Image builds locally (bun run build:docker)
- /health, /openapi.yaml, /docs, /metrics, /shade-observer all respond
- 401 without observer token, 200 with
- Real SDK client round-trip: Alice → container → Bob → reply → Alice
- Persistence: identity + prekeys survive container restart (count 20→18
  as expected from two bundle fetches)

285 tests passing, 0 failures.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

README.md

@@ -154,25 +154,28 @@ bun run publish:all
 - [examples/](./examples/) — Runnable example applications
 - [MIGRATION.md](./MIGRATION.md) — How to replace existing crypto with Shade
 
-## Deployment
+## Deployment — one container per project
 
-For containerized deployment (Docker/Dokploy):
+Shade ships as a self-contained Docker image. Deploy one container per project, point your app at it, done. Any stack (Bun, Python, Go, Rust, Kotlin) can use it — the container exposes a plain HTTP API documented in OpenAPI.
 
-```yaml
-services:
-  shade-prekey:
-    image: shade-prekey-server:latest
-    ports:
-      - "3900:3900"
-    volumes:
-      - shade-data:/data
-    environment:
-      - SHADE_PREKEY_DB_PATH=/data/shade-prekeys.db
-volumes:
-  shade-data:
+```bash
+docker run -d \
+  --name my-project-shade \
+  -v my-project-shade:/data \
+  -p 3900:3900 \
+  -e SHADE_OBSERVER_TOKEN=change-me-to-at-least-16-chars \
+  gt.zyon.no/stian/shade-prekey:latest
 ```
 
-The SQLite database persists to a Docker volume so all keys and prekey bundles survive restarts.
+The container includes:
+- **Prekey server** — `/v1/keys/*` REST API
+- **Observer dashboard** — `/shade-observer/dashboard/` (off unless token is set)
+- **OpenAPI spec** — `/openapi.yaml` and interactive `/docs` viewer
+- **Prometheus metrics** — `/metrics`
+- **Health check** — `/health`
+- **Stale cleanup** — purges inactive identities automatically
+
+See [docs/DEPLOYMENT.md](./docs/DEPLOYMENT.md) for the full deployment guide, environment variables, PostgreSQL config, backup strategy, and Dokploy instructions.
 
 ## License