feat(client): C 端 1-2 账号链路（邮箱登录/注册 + 令牌与 401 + 匿名/登录分叉）

为什么：客户端此前完全没有账号概念（mine 页的"登录"只是本地 demo 开关），
而受限动作（收藏/评论）要对到具体账号。本批把账号链路接上，为后续互动、进度同步、下载打底。

- AuthApi + AuthController + AuthSessionStore：注册/登录/登出/刷新，令牌与设备号存 shared_preferences
  （用 SharedPreferencesAsync，与 engagement 仓库同一套 API）
- ApiClient：统一带 Authorization 与 X-Device-Id；401 自动刷新一次并重试，刷新失败清登录态走 onUnauthorized
- 登录/注册页（pages/auth，沿用 binding/logic/view 与现有视觉）：邮箱格式、密码 8-64 位含字母数字本地先校验，
  错误提示走 l10n；登录/注册一键切换
- 匿名/登录分叉：首页、发现、详情保持匿名可看；收藏/点赞等受限动作走 ensureSignedIn() 弹底部提示引导登录
- mine 页展示真实账号（昵称 + uid），拿不到才回落到演示文案
- 测试：新增 auth 控制器（注册落盘/401 刷新重试/刷新失败清会话/登出）与登录页（校验/切换）用例；
  widget_test 改为预置本地会话（账号不再是本地开关）；修掉 playback 用例对 host 大小写的环境依赖断言

门禁：flutter analyze 0 问题；flutter test 148 全过。

lib/app.dart

@@ -2,8 +2,13 @@ import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
 import 'core/config/locale_controller.dart';
+import 'core/data/remote/api_client.dart';
+import 'core/data/remote/auth_api.dart';
+import 'core/data/remote/catalog_api.dart';
 import 'core/data/repositories/catalog_repository.dart';
 import 'core/data/repositories/engagement_repository.dart';
+import 'core/data/services/auth_controller.dart';
+import 'core/data/services/auth_session_store.dart';
 import 'core/data/services/catalog_controller.dart';
 import 'core/data/services/engagement_controller.dart';
 import 'core/data/services/playback_session.dart';
@@ -11,19 +16,53 @@ import 'core/data/services/video_player_port.dart';
 import 'l10n/app_localizations.dart';
 import 'pages/home/home_view.dart';
 
-class LumaDramaApp extends StatelessWidget {
-  const LumaDramaApp({super.key, this.playerFactory = VideoPlayerPort.new});
+class LumaDramaApp extends StatefulWidget {
+  const LumaDramaApp({
+    super.key,
+    this.playerFactory = VideoPlayerPort.new,
+    this.catalogRepository,
+  });
 
   final PlayerFactory playerFactory;
 
+  /// 测试注入用；生产走 HTTP 仓库。
+  final CatalogRepository? catalogRepository;
+
+  @override
+  State<LumaDramaApp> createState() => _LumaDramaAppState();
+}
+
+class _LumaDramaAppState extends State<LumaDramaApp> {
+  late final AuthSessionStore _sessionStore = AuthSessionStore();
+
+  /// 全 App 共用一个 ApiClient：这样目录、账号、后续的互动/进度请求
+  /// 都自动带 `Authorization` 与 `X-Device-Id`，401 的刷新重试也只有一处实现。
+  late final ApiClient _apiClient = ApiClient(
+    accessTokenReader: () => _auth.accessToken,
+    tokenRefresher: () => _auth.refresh(),
+    onUnauthorized: () => _auth.clear(),
+    deviceIdReader: _sessionStore.deviceId,
+  );
+
+  late final AuthController _auth = AuthController(AuthApi(_apiClient), _sessionStore);
+
+  @override
+  void initState() {
+    super.initState();
+    // 恢复本地令牌与设备号；未登录也能正常浏览，不阻塞首屏
+    _auth.load();
+  }
+
   @override
   Widget build(BuildContext context) {
     return MultiProvider(
       providers: [
         Provider(create: (_) => PlaybackCoordinator()),
-        Provider<PlayerFactory>(create: (_) => playerFactory),
+        Provider<PlayerFactory>(create: (_) => widget.playerFactory),
         ChangeNotifierProvider(
-          create: (_) => CatalogController(DemoCatalogRepository())..load(),
+          create: (_) => CatalogController(
+            widget.catalogRepository ?? HttpCatalogRepository(CatalogApi(_apiClient)),
+          )..load(),
         ),
         ChangeNotifierProvider(create: (_) => LocaleController()..load()),
         ChangeNotifierProvider(
@@ -31,6 +70,7 @@ class LumaDramaApp extends StatelessWidget {
               EngagementController(SharedPreferencesEngagementRepository())
                 ..load(),
         ),
+        ChangeNotifierProvider.value(value: _auth),
       ],
       child: Consumer<LocaleController>(
         builder: (context, locale, _) => MaterialApp(
@@ -51,14 +91,14 @@ class LumaDramaApp extends StatelessWidget {
           theme: ThemeData(
             useMaterial3: true,
             colorScheme: ColorScheme.fromSeed(
-              seedColor: const Color(0xFF6D4AFF),
+              seedColor: const Color(0xFF2F7BFF),
             ),
             scaffoldBackgroundColor: const Color(0xFFF8F7FC),
           ),
           darkTheme: ThemeData(
             useMaterial3: true,
             colorScheme: ColorScheme.fromSeed(
-              seedColor: const Color(0xFF9B86FF),
+              seedColor: const Color(0xFF2F7BFF),
               brightness: Brightness.dark,
             ),
             scaffoldBackgroundColor: const Color(0xFF101019),