fix(api-gateway): 增加文件上传大小限制到 500MB

- Kong request-size-limiting: 50MB -> 500MB
- Nginx client_max_body_size: 100M -> 500M

用于支持大型 APK/IPA 文件上传

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

backend/api-gateway/kong.yml

@@ -221,10 +221,10 @@ plugins:
       path: /tmp/kong-access.log
       reopen: true
 
-  # 请求/响应大小限制
+  # 请求/响应大小限制 (500MB 用于 APK/IPA 上传)
   - name: request-size-limiting
     config:
-      allowed_payload_size: 50
+      allowed_payload_size: 500
       size_unit: megabytes
 
   # Prometheus 监控指标

backend/api-gateway/nginx/rwaapi.szaiai.com.conf

@@ -61,8 +61,8 @@ server {
     add_header X-XSS-Protection "1; mode=block" always;
     add_header Referrer-Policy "strict-origin-when-cross-origin" always;
 
-    # 客户端请求大小限制 (用于文件上传)
-    client_max_body_size 100M;
+    # 客户端请求大小限制 (500MB 用于 APK/IPA 上传)
+    client_max_body_size 500M;
 
     # 反向代理到 Kong API Gateway
     location / {