Token自动刷新机制：QueuedInterceptor实现无感刷新，只有彻底过期才跳转登录

flutter_monisuo/lib/providers/auth_provider.dart

@@ -90,6 +90,7 @@ class AuthProvider extends ChangeNotifier {
     String? message,
   ) {
     _token = data['token'] as String?;
+    final refreshToken = data['refreshToken'] as String?;
     final userJson = data['user'] as Map<String, dynamic>? ??
         data['userInfo'] as Map<String, dynamic>?;
 
@@ -97,6 +98,11 @@ class AuthProvider extends ChangeNotifier {
       LocalStorage.saveToken(_token!);
     }
 
+    // 保存 refreshToken（後端實現後生效）
+    if (refreshToken != null && refreshToken.isNotEmpty) {
+      LocalStorage.saveRefreshToken(refreshToken);
+    }
+
     if (userJson != null) {
       LocalStorage.saveUserInfo(userJson);
       _user = User.fromJson(userJson);