fix: improve transfer recognition and local data safety

frontend/test/visual_contract_test.dart

@@ -3,6 +3,21 @@ import 'dart:io';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {
+  test('登录强制刷新远端资料并按后端隔离本地账号数据', () {
+    final auth = File('lib/shared/api/auth_api.dart').readAsStringSync();
+    final session = File(
+      'lib/shared/services/session_store.dart',
+    ).readAsStringSync();
+
+    expect(auth, contains('me(forceRemote: true)'));
+    expect(auth, contains('if (!forceRemote &&'));
+    expect(session, contains('BackendIdentity.accountNamespace(userId)'));
+    expect(session, contains('pending_account_archive_namespace'));
+    expect(session, contains('last_account_namespace'));
+    final client = File('lib/shared/api/api_client.dart').readAsStringSync();
+    expect(client, contains("'auth_token_\${BackendIdentity.scope}'"));
+  });
+
   test('启动页只读取本地缓存，不等待远程接口', () {
     final source = File(
       'lib/features/auth/pages/splash_page.dart',