添加 backend 微服务架构：Nginx 网关 + user-service 登录注册

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

@@ -0,0 +1,39 @@
+# 用户服务路由
+location /api/v1/users {
+    # 限流
+    limit_req zone=general burst=20 nodelay;
+    limit_conn addr 10;
+
+    # 代理设置
+    proxy_pass http://user_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;
+    
+    # WebSocket 支持（如果需要）
+    proxy_set_header Upgrade $http_upgrade;
+    proxy_set_header Connection "upgrade";
+    
+    # 缓存控制
+    proxy_cache_bypass $http_upgrade;
+    proxy_no_cache 1;
+}
+
+# 认证相关接口（严格限流）
+location /api/v1/auth {
+    limit_req zone=api_strict burst=5 nodelay;
+    limit_conn addr 3;
+    
+    proxy_pass http://user_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;
+}