refactor: 前端 UI 框架从 TDesign 迁移到 antd 6.x

- 移除 tdesign-react + tdesign-icons-react，新增 antd@6.4.3 + @ant-design/icons@6.2.3
- Layout/Header/Sider/Content 替换 TDesign Layout，Sider 内置折叠管理
- Segmented 替换 RadioGroup 主题切换，ConfigProvider 主题算法切换
- Menu items prop 模式，Sidebar 简化为无 props 纯组件
- Table/Modal/Form/Input.TextArea/Tabs/Tag/Popconfirm 全量迁移
- App.useApp().message 替换 MessagePlugin（hooks 模式）
- --td-* CSS 变量替换为 --ant-* antd CSS 变量
- 测试适配：ConfigProvider+App wrapper，.ant-menu-item-selected，antd CSS-in-JS jsdom 兼容
- 文档更新：frontend.md, development/README.md, config.yaml, deploy.md
- vendor-antd chunk 755KB gzipped 240KB

opencode.json

@@ -5,6 +5,12 @@
       "enabled": true,
       "type": "local",
       "command": ["bunx", "tdesign-mcp-server@latest"]
+    },
+    "antd": {
+      "enabled": true,
+      "type": "local",
+      "command": ["bunx", "-y", "@ant-design/cli", "mcp"],
+      "timeout": 10000
     }
   }
 }