feat(auth): 接入 Google 登录

- 登录页保留邮箱与 Google 两个入口，Google 按钮按官方规范改为白底四色图标
- 新增 GoogleAuthService：封装 initialize/authenticate，失败以结果对象返回
- AuthApi 增加 googleLogin，AuthController 增加 signInWithGoogle
- iOS 补充 CFBundleURLTypes 与 GIDClientID，Bundle ID 统一为 com.stormg.lumadrama
- Google 请求期间按钮显示转圈并禁止重复点击

test/auth/auth_landing_test.dart

@@ -53,22 +53,15 @@ void main() {
     );
     await tester.pumpAndSettle();
 
-    expect(find.byKey(const Key('auth-entry-google')), findsNothing);
-    expect(find.byKey(const Key('auth-entry-phone')), findsOneWidget);
+    expect(find.byKey(const Key('auth-entry-phone')), findsNothing);
     expect(find.byKey(const Key('auth-entry-email')), findsOneWidget);
+    expect(find.byKey(const Key('auth-entry-google')), findsOneWidget);
     expect(find.byKey(const Key('auth-legal')), findsOneWidget);
     expect(
       tester.getTopLeft(find.byKey(const Key('auth-landing'))).dy,
       lessThan(80),
     );
 
-    await tester.tap(find.byKey(const Key('auth-entry-phone')));
-    await tester.pumpAndSettle();
-    expect(find.byKey(const Key('phone-auth-sheet')), findsOneWidget);
-
-    await tester.tapAt(const Offset(8, 8));
-    await tester.pumpAndSettle();
-
     await tester.tap(find.byKey(const Key('auth-entry-email')));
     await tester.pumpAndSettle();
     expect(find.byKey(const Key('auth-email')), findsOneWidget);