fix(api): graceful shutdown, единый обработчик ошибок и корректные 404

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

docker-compose.yml

@@ -23,6 +23,8 @@ services:
     volumes:
       - ./data:/data
     restart: unless-stopped
+    init: true
+    stop_grace_period: 15s
     healthcheck:
       test: ["CMD", "node", "-e", "fetch('http://127.0.0.1:8080/health').then(r=>process.exit(r.ok?0:1)).catch(()=>process.exit(1))"]
       interval: 30s