完善Token刷新架构：后端实现refreshToken轮转机制

后端：
- JwtUtil: accessToken 2h + refreshToken 30d，区分type
- AuthController: POST /api/auth/refresh 接口
- AuthService: 验证refreshToken → 轮转生成新token对
- UserService: 登录/注册返回refreshToken
- User entity: 添加refreshToken字段
- TokenFilter: 排除/api/auth/refresh路径
- SQL: sys_user添加refresh_token列

前端：
- DioClient: 刷新成功后同时保存新的refreshToken

flutter_monisuo/build/web/flutter_bootstrap.js

@@ -37,6 +37,6 @@ _flutter.buildConfig = {"engineRevision":"e4b8dca3f1b4ede4c30371002441c88c12187e
 
 _flutter.loader.load({
   serviceWorkerSettings: {
-    serviceWorkerVersion: "1911676977" /* Flutter's service worker is deprecated and will be removed in a future Flutter release. */
+    serviceWorkerVersion: "112731293" /* Flutter's service worker is deprecated and will be removed in a future Flutter release. */
   }
 });