feat: 完成网关服务代码实现，支持 WebSocket 长连接与健康检查

backend/Makefile

@@ -0,0 +1,18 @@
+# Makefile for backend services
+
+.PHONY: build up down logs
+
+build:
+	docker-compose build
+
+up:
+	docker-compose up -d
+
+down:
+	docker-compose down
+
+logs:
+	docker-compose logs -f
+
+status:
+	docker-compose ps