fixed logout at refresh failed

lib/core/network/network_manager.dart

@@ -17,6 +17,14 @@ class NetworkManager {
   bool _interceptorsAdded = false;
   final SharedPreferences _prefs;
 
+  /// Callback invoked when refresh token fails (expired, missing, or errored).
+  /// Should clear local auth state and navigate to the login screen.
+  /// // Callback to be called when refresh token fails (logout callback)
+  Future<void> Function()? _onAuthFailed;
+  void setAuthFailed(Future<void> Function() callback) {
+    _onAuthFailed = callback;
+  }
+
   NetworkManager(this._prefs)
     : mainDio = Dio(
         BaseOptions(
@@ -75,6 +83,10 @@ class NetworkManager {
             mainDio.options.headers['Authorization'] = 'Bearer $newAccessToken';
             return handler.resolve(await mainDio.fetch(error.requestOptions));
           }
+
+          // Refresh token failed – force logout
+          appLogger.error('❌ Refresh token failed, triggering logout');
+          await _onAuthFailed!();
         }
         return handler.next(error);
       },