Phase 9: Admin & DevOps — health check, rate limiting, logging, site admin, Docker healthcheck

- Health check endpoint (GET /api/health) with DB probe and uptime
- In-memory sliding window rate limiting on login (10/60s) and register (5/3600s)
- Structured logging with pino (request timing in hooks, Socket.IO events in server.js)
- Site admin dashboard with tenant stats, CRUD, and requireSiteAdmin guard
- Tenant admin enhanced with tag and category management UI
- Docker HEALTHCHECK in Dockerfile and docker-compose.yml
- Backup documentation (docs/backup.md)

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

docker-compose.yml

@@ -30,6 +30,12 @@ services:
     depends_on:
       db:
         condition: service_healthy
+    healthcheck:
+      test: ['CMD', 'curl', '-f', 'http://localhost:3000/api/health']
+      interval: 30s
+      timeout: 5s
+      start_period: 10s
+      retries: 3
     volumes:
       - uploads:/app/uploads