feat(api): implement rate limiting for abuse prevention

Add @fastify/rate-limit with granular policies for different routes
Support TRUST_PROXY environment variable for reverse proxies

docker-compose.yml

@@ -22,6 +22,7 @@ services:
     environment:
       DATABASE_URL: postgres://pokopia:pokopia@postgres:5432/pokopia
       BACKEND_PORT: 3001
+      TRUST_PROXY: ${TRUST_PROXY:-false}
       FRONTEND_ORIGIN: http://localhost:20015
       APP_ORIGIN: http://localhost:20015
       UPLOAD_DIR: /app/uploads