feat(WP-0004): railiance deployment & service ops

- Dockerfile (multi-stage, uv-based, slim runtime)
- .dockerignore
- docker-compose.railiance.yml (Temporal + NATS + PG, no Elasticsearch)
- GET /health endpoint (db + temporal probes, 200/503)
- .env.example (complete env var reference)
- Makefile: migrate, sync-all, dev-up/down, railiance-up/down,
  start-worker, start-api, start-event-router, help targets;
  extracted sync-event-types Python to scripts/sync_event_types.py
- SIGTERM graceful shutdown in worker.py and event_router.py
- docs/runbook.md: Railiance deployment section

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.dockerignore

@@ -0,0 +1,7 @@
+.venv/
+__pycache__/
+*.pyc
+.git/
+tests/
+*.egg-info/
+.env