feat: 增强 Chat 能力并补充单机部署方案

完善会话消息删除、Qwen 联网搜索/深度思考参数与 SSE 来源事件，同时增加请求体日志与 TS6 配置兼容调整，并新增 Ubuntu+PM2+Nginx 的部署文档与脚本以支持可回滚发布。

Made-with: Cursor

deploy/nginx/chat-one-service.conf

@@ -0,0 +1,22 @@
+server {
+  listen 80;
+  server_name api.example.com;
+
+  client_max_body_size 20m;
+
+  location / {
+    proxy_pass http://127.0.0.1:3000;
+    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;
+
+    # SSE support
+    proxy_buffering off;
+    proxy_cache off;
+    proxy_read_timeout 3600;
+    proxy_send_timeout 3600;
+    chunked_transfer_encoding off;
+  }
+}