로그인 챌린지 루프 방지 가드 추가

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

@@ -9,6 +9,7 @@ import '../../../core/widgets/language_selector.dart';
 import '../../../core/services/web_auth_integration.dart';
 import '../../../core/services/auth_proxy_service.dart';
 import '../../../core/services/auth_token_store.dart';
+import '../../../core/services/login_challenge_loop_guard.dart';
 import '../../../core/i18n/locale_utils.dart';
 import '../../../core/services/oidc_redirect_guard.dart';
 import '../../../core/notifiers/auth_notifier.dart';
@@ -143,7 +144,11 @@ class _LoginScreenState extends ConsumerState<LoginScreen>
       if (!_verificationOnly) {
         await _attemptOidcAutoAccept();
         if (!mounted) return;
-        await _tryCookieSession();
+        // login_challenge 흐름에서는 auto-accept에서 이미 쿠키 세션까지 확인하므로
+        // 동일 프레임에서 중복 체크를 피합니다.
+        if (!_hasLoginChallenge) {
+          await _tryCookieSession();
+        }
       }
     });
   }
@@ -239,11 +244,19 @@ class _LoginScreenState extends ConsumerState<LoginScreen>
     if (loginChallenge == null || loginChallenge.isEmpty) {
       return;
     }
+    if (!loginChallengeLoopGuard.shouldAllowAutoAccept(loginChallenge)) {
+      debugPrint(
+        "[Auth] OIDC auto-accept blocked by loop guard for login_challenge",
+      );
+      return;
+    }
+    loginChallengeLoopGuard.markAutoAcceptAttempt(loginChallenge);
 
     final token = AuthTokenStore.getToken();
     if (token != null && token.isNotEmpty) {
       final accepted = await _acceptOidcLoginAndRedirect(token: token);
       if (accepted) {
+        loginChallengeLoopGuard.clear(loginChallenge);
         return;
       }
     }
@@ -255,7 +268,11 @@ class _LoginScreenState extends ConsumerState<LoginScreen>
         AuthTokenStore.setCookieMode(
           provider: AuthTokenStore.getProvider() ?? 'ory',
         );
-        await _acceptOidcLoginAndRedirect();
+        final accepted = await _acceptOidcLoginAndRedirect();
+        if (accepted) {
+          loginChallengeLoopGuard.clear(loginChallenge);
+          return;
+        }
       } else {
         debugPrint(
           "[Auth] OIDC auto-accept: No active session (status: $status)",
@@ -1216,6 +1233,7 @@ class _LoginScreenState extends ConsumerState<LoginScreen>
           final nextRedirectTo = res['redirectTo'] as String?;
 
           if (nextRedirectTo != null && nextRedirectTo.isNotEmpty) {
+            loginChallengeLoopGuard.clear(loginChallenge);
             webWindow.redirectTo(nextRedirectTo); // Removed await
             return;
           } else {}