feat(auth): 优化登录页布局与字段反馈

lib/l10n/app_localizations_zh.dart

@@ -643,6 +643,9 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get authSubtitle => '用邮箱和密码登录。';
 
+  @override
+  String get authSignUpSubtitle => '创建账号，保存你的片单、观看记录和进度。';
+
   @override
   String get authBrandTagline => '为印尼市场打造的短剧体验';