리다이렉트 후속 로직 업데이트

userfront/test/oidc_redirect_guard_test.dart

@@ -0,0 +1,36 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:userfront/core/services/oidc_redirect_guard.dart';
+
+void main() {
+  group('oidc_redirect_guard', () {
+    test('http/https 절대 URL만 허용', () {
+      final ok = validateOidcRedirectTarget(
+        'https://sso-test.hmac.kr/oidc/oauth2/auth?client_id=devfront&login_verifier=abc',
+      );
+      expect(ok.isValid, isTrue);
+      expect(ok.reason, 'ok');
+      expect(ok.host, 'sso-test.hmac.kr');
+      expect(ok.path, '/oidc/oauth2/auth');
+      expect(ok.hasLoginVerifier, isTrue);
+
+      final relative = validateOidcRedirectTarget('/oidc/oauth2/auth');
+      expect(relative.isValid, isFalse);
+      expect(relative.reason, 'not_absolute');
+
+      final js = validateOidcRedirectTarget('javascript:alert(1)');
+      expect(js.isValid, isFalse);
+      expect(js.reason, 'not_absolute');
+    });
+
+    test('빈 문자열과 파싱 실패를 차단', () {
+      final empty = validateOidcRedirectTarget('   ');
+      expect(empty.isValid, isFalse);
+      expect(empty.reason, 'empty');
+      expect(empty.length, 0);
+
+      final malformed = validateOidcRedirectTarget('https://[broken');
+      expect(malformed.isValid, isFalse);
+      expect(malformed.reason, 'parse_error');
+    });
+  });
+}