feat: i18n 개선 및 userfront 로그인/로케일 보완

userfront/lib/features/auth/presentation/login_success_screen.dart

@@ -14,23 +14,26 @@ class LoginSuccessScreen extends StatelessWidget {
           child: Column(
             mainAxisAlignment: MainAxisAlignment.center,
             children: [
-              const Icon(Icons.check_circle_outline, size: 80, color: Colors.green),
+              const Icon(
+                Icons.check_circle_outline,
+                size: 80,
+                color: Colors.green,
+              ),
               const SizedBox(height: 24),
               Text(
-                tr('ui.userfront.login_success.title', fallback: '로그인 완료'),
-                style: TextStyle(
-                  fontSize: 32,
-                  fontWeight: FontWeight.bold,
-                ),
+                tr('ui.userfront.login_success.title'),
+                style: TextStyle(fontSize: 32, fontWeight: FontWeight.bold),
               ),
               const SizedBox(height: 16),
               Text(
-                tr('msg.userfront.login_success.subtitle', fallback: '성공적으로 로그인되었습니다.'),
+                tr(
+                  'msg.userfront.login_success.subtitle',
+                ),
                 textAlign: TextAlign.center,
                 style: const TextStyle(color: Colors.grey, fontSize: 16),
               ),
               const SizedBox(height: 48),
-              
+
               // 이 버튼이 QR 카메라를 켜는 버튼입니다.
               FilledButton.icon(
                 onPressed: () {
@@ -38,12 +41,17 @@ class LoginSuccessScreen extends StatelessWidget {
                 },
                 icon: const Icon(Icons.camera_alt, size: 28),
                 label: Text(
-                  tr('ui.userfront.login_success.qr', fallback: 'QR 인증 (카메라 켜기)'),
+                  tr(
+                    'ui.userfront.login_success.qr',
+                  ),
                 ),
                 style: FilledButton.styleFrom(
                   minimumSize: const Size.fromHeight(80), // 버튼 높이를 더 크게
                   backgroundColor: Colors.blue.shade700,
-                  textStyle: const TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
+                  textStyle: const TextStyle(
+                    fontSize: 20,
+                    fontWeight: FontWeight.bold,
+                  ),
                   shape: RoundedRectangleBorder(
                     borderRadius: BorderRadius.circular(16),
                   ),
@@ -57,7 +65,6 @@ class LoginSuccessScreen extends StatelessWidget {
                 child: Text(
                   tr(
                     'ui.userfront.login_success.later',
-                    fallback: '나중에 하기 (대시보드로 이동)',
                   ),
                   style: const TextStyle(color: Colors.grey),
                 ),