feat(client): 实时授权状态与会话失效处理

- 心跳读取 /auth/ping 回带的授权概况，直接刷新横幅/状态栏/只读门禁，省去单独轮询 /license/info
- 账号被停用/删除（401 USER_DISABLED）即强制重新登录
- 令牌持久化经串行队列 + 会话代号守卫，杜绝续期写入与登出交叉把失效 token 写回
- 写操作门禁（write_guard）+ 授权文案（license_copy）按 grace/readonly/locked 分阶段降级

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/test/partners_screen_test.dart

@@ -4,10 +4,25 @@ import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:jiu_client/core/models/page_result.dart';
+import 'package:jiu_client/models/license.dart';
 import 'package:jiu_client/models/partner.dart';
+import 'package:jiu_client/providers/license_provider.dart';
 import 'package:jiu_client/providers/partner_provider.dart';
 import 'package:jiu_client/screens/partners/partners_screen.dart';
 
+/// WriteGuard 内层会 watch licenseProvider；测试里覆写成同步返回 normal 授权，
+/// 避免触发真实网络请求（否则留下 pending timer 导致测试失败）。
+class _FakeLicenseNotifier extends LicenseNotifier {
+  @override
+  Future<LicenseInfo?> build() async => const LicenseInfo(
+        id: 1,
+        type: 'annual',
+        isActive: true,
+        maxDevices: 3,
+        phase: 'normal',
+      );
+}
+
 // ---------------------------------------------------------------------------
 // Fake notifier
 // ---------------------------------------------------------------------------
@@ -80,6 +95,7 @@ Widget _buildApp({
 }) {
   return ProviderScope(
     overrides: [
+      licenseProvider.overrideWith(() => _FakeLicenseNotifier()),
       supplierListProvider.overrideWith(
         () => _FakePartnerNotifier('supplier', supplierState),
       ),
@@ -94,6 +110,7 @@ Widget _buildApp({
 Widget _buildLoadingApp() {
   return ProviderScope(
     overrides: [
+      licenseProvider.overrideWith(() => _FakeLicenseNotifier()),
       supplierListProvider.overrideWith(
         () => _FakeLoadingPartnerNotifier('supplier'),
       ),