feat: 新增登录页 + 主题改橙红对齐设计稿

- 新增登录页（Google / 手机号 / 邮箱 + 游客浏览 + 首登送金币）
- seedColor 改橙红 #FF5B3D，themeMode 改 dark，背景对齐设计稿 #0B0C10
- app 启动入口改为 LoginPage

lib/app.dart

@@ -11,7 +11,7 @@ import 'core/data/services/engagement_controller.dart';
 import 'core/data/services/playback_session.dart';
 import 'core/data/services/video_player_port.dart';
 import 'l10n/app_localizations.dart';
-import 'pages/home/home_view.dart';
+import 'pages/login/login_view.dart';
 
 class LumaDramaApp extends StatelessWidget {
   const LumaDramaApp({super.key, this.playerFactory = VideoPlayerPort.new});
@@ -49,23 +49,23 @@ class LumaDramaApp extends StatelessWidget {
             return supported.first;
           },
           debugShowCheckedModeBanner: false,
-          themeMode: ThemeMode.system,
+          themeMode: ThemeMode.dark,
           theme: ThemeData(
             useMaterial3: true,
             colorScheme: ColorScheme.fromSeed(
-              seedColor: const Color(0xFF6D4AFF),
+              seedColor: const Color(0xFFFF5B3D),
             ),
-            scaffoldBackgroundColor: const Color(0xFFF8F7FC),
+            scaffoldBackgroundColor: const Color(0xFF0B0C10),
           ),
           darkTheme: ThemeData(
             useMaterial3: true,
             colorScheme: ColorScheme.fromSeed(
-              seedColor: const Color(0xFF9B86FF),
+              seedColor: const Color(0xFFFF5B3D),
               brightness: Brightness.dark,
             ),
-            scaffoldBackgroundColor: const Color(0xFF101019),
+            scaffoldBackgroundColor: const Color(0xFF0B0C10),
           ),
-          home: const HomePage(),
+          home: const LoginPage(),
         ),
       ),
     );