test(client): app 外壳（顶栏/侧栏/状态栏）整壳 golden ×三主题

外壳 chrome 是最显眼的主题面，但各屏 golden 都不含它。本 golden 用
MaterialApp.router + StatefulNavigationShell 渲染整壳（覆盖 auth/shop/license/
update/connectivity/heartbeat，跳过联网首检与心跳避免 Timer 泄漏），锁住
顶栏+侧栏+状态栏随 A/B/C 换色入回归闸。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TSKEiHsvauyxYUW2itzUXX

client/test/golden/app_shell_golden_test.dart

@@ -0,0 +1,101 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:go_router/go_router.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import 'package:jiu_client/core/auth/auth_state.dart';
+import 'package:jiu_client/core/theme/themes.dart';
+import 'package:jiu_client/models/shop.dart';
+import 'package:jiu_client/providers/shop_provider.dart';
+import 'package:jiu_client/providers/license_provider.dart';
+import 'package:jiu_client/providers/update_provider.dart';
+import 'package:jiu_client/providers/connectivity_provider.dart';
+import 'package:jiu_client/providers/session_heartbeat.dart';
+import 'package:jiu_client/screens/shell/app_shell.dart';
+
+/// design-distill 阶段4：app 外壳（顶栏 + 侧栏 + 内容区）golden × 三主题。
+/// 锁住导航 chrome 随主题换色——这是最显眼的主题面，之前各屏 golden 都不含外壳。
+/// 需 MaterialApp.router（外壳依赖 StatefulNavigationShell），故为自定义 golden。
+/// 更新基准：flutter test --update-goldens test/golden/app_shell_golden_test.dart
+
+class _FakeAuth extends AuthNotifier {
+  _FakeAuth() {
+    state = const AuthState(
+      user: AuthUser(
+          accessToken: 't', refreshToken: 'r', id: 1, username: 'wang',
+          realName: '王经理', shopNo: 'DBZB-001', shopId: 1, role: 'admin'),
+    );
+  }
+}
+
+class _FakeUpdate extends UpdateNotifier {
+  @override
+  Future<AppUpdateInfo?> build() async => null;
+}
+
+class _FakeLicense extends LicenseNotifier {
+  @override
+  Future<LicenseInfo?> build() async => null;
+}
+
+const _shop = ShopInfo(
+    id: 1, code: 'DBZB-001', name: '鼎昌酒行',
+    address: '浙江省杭州市', phone: '0571-88886666', managerName: '王经理');
+
+List<Override> _overrides() => [
+      authStateProvider.overrideWith((ref) => _FakeAuth()),
+      shopInfoProvider.overrideWith((ref) => _shop),
+      licenseProvider.overrideWith(() => _FakeLicense()),
+      updateProvider.overrideWith(() => _FakeUpdate()),
+      // 跳过联网首检 / 不启动心跳，避免后台 Timer 泄漏
+      connectivityProvider
+          .overrideWith((ref) => ConnectivityNotifier(skipInit: true)),
+      sessionHeartbeatProvider.overrideWith((ref) => SessionHeartbeat(ref)),
+      appVersionProvider.overrideWith((ref) => 'v1.0.72'),
+      isReadonlyProvider.overrideWithValue(false),
+    ];
+
+GoRouter _router() => GoRouter(
+      initialLocation: '/inventory',
+      routes: [
+        StatefulShellRoute.indexedStack(
+          builder: (ctx, state, shell) => AppShell(navigationShell: shell),
+          branches: [
+            StatefulShellBranch(routes: [
+              GoRoute(
+                  path: '/inventory',
+                  builder: (_, __) => const SizedBox.expand()),
+            ]),
+          ],
+        ),
+      ],
+    );
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+  SharedPreferences.setMockInitialValues({});
+
+  for (final theme in const ['a', 'b', 'c']) {
+    testWidgets('app shell · theme $theme', (tester) async {
+      tester.view.physicalSize = const Size(2560, 1600);
+      tester.view.devicePixelRatio = 2.0;
+      addTearDown(tester.view.resetPhysicalSize);
+      addTearDown(tester.view.resetDevicePixelRatio);
+
+      await tester.pumpWidget(ProviderScope(
+        overrides: _overrides(),
+        child: MaterialApp.router(
+          debugShowCheckedModeBanner: false,
+          theme: buildTheme(theme),
+          routerConfig: _router(),
+        ),
+      ));
+      await tester.pumpAndSettle();
+
+      await expectLater(
+        find.byType(MaterialApp),
+        matchesGoldenFile('goldens/app_shell_$theme.png'),
+      );
+    });
+  }
+}