重构项目结构：统一目录层级

- 移除 backend/.git 工作树配置
- 将原根目录文件归入 backend/ 目录
- 新增 app/、frontend/ 等模块
- 保留文件历史（自动识别重命名）

backend/gateway/nginx/conf.d/services/order-service.conf

@@ -0,0 +1,29 @@
+# 订单服务路由
+location /api/v1/orders {
+    limit_req zone=general burst=30 nodelay;
+    limit_conn addr 10;
+    
+    proxy_pass http://order_service;
+    proxy_http_version 1.1;
+    
+    proxy_set_header Host $host;
+    proxy_set_header X-Real-IP $remote_addr;
+    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+    proxy_set_header X-Forwarded-Proto $scheme;
+    proxy_set_header X-Request-ID $request_id;
+}
+
+# 购物车接口
+location /api/v1/cart {
+    limit_req zone=general burst=20 nodelay;
+    limit_conn addr 10;
+    
+    proxy_pass http://order_service;
+    proxy_http_version 1.1;
+    
+    proxy_set_header Host $host;
+    proxy_set_header X-Real-IP $remote_addr;
+    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+    proxy_set_header X-Forwarded-Proto $scheme;
+    proxy_set_header X-Request-ID $request_id;
+}