i18n 대대적 변경

userfront/lib/main.dart

@@ -21,6 +21,7 @@ import 'core/services/logger_service.dart';
 import 'core/notifiers/auth_notifier.dart';
 import 'package:logging/logging.dart';
 import 'features/auth/presentation/consent_screen.dart';
+import 'i18n.dart';
 
 final _log = Logger('Main');
 
@@ -200,9 +201,12 @@ final _router = GoRouter(
       path: '/settings',
       builder: (context, state) {
         _routerLogger.info("Navigating to /settings (disabled)");
-        return const ErrorScreen(
+        return ErrorScreen(
           errorCode: 'settings_disabled',
-          description: '현재 계정 설정 화면은 준비 중입니다.',
+          description: tr(
+            'msg.userfront.settings.disabled',
+            fallback: '현재 계정 설정 화면은 준비 중입니다.',
+          ),
         );
       },
     ),
@@ -295,7 +299,7 @@ class BaronSSOApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp.router(
-      title: 'Baron 로그인',
+      title: tr('ui.userfront.app_title', fallback: 'Baron 로그인'),
       theme: ThemeData(
         colorScheme: ColorScheme.fromSeed(
           seedColor: const Color(0xFF1A1F2C), // Dark Navy/Black base