tenant 제한 에러 처리 보안

userfront/test/consent_error_routing_test.dart

@@ -20,4 +20,33 @@ void main() {
 
     expect(shouldRouteConsentErrorToErrorScreen(error), isFalse);
   });
+
+  test('tenant_not_allowed auth error also routes to error screen', () {
+    const error = AuthProxyException(
+      errorCode: 'tenant_not_allowed',
+      message: '허용되지 않은 테넌트입니다.',
+    );
+
+    expect(shouldRouteTenantAccessErrorToErrorScreen(error), isTrue);
+  });
+
+  test('buildTenantAccessErrorPath builds userfront error route', () {
+    const error = AuthProxyException(
+      errorCode: 'tenant_not_allowed',
+      message: '허용되지 않은 테넌트입니다.',
+      details: {
+        'allowed_tenants': ['tenant-a'],
+      },
+    );
+
+    final target = buildTenantAccessErrorPath(
+      error,
+      Uri.parse('https://sso-test.hmac.kr/ko?login_challenge=abc'),
+    );
+
+    expect(target, contains('/error?'));
+    expect(target, contains('error=tenant_not_allowed'));
+    expect(target, contains('error_description='));
+    expect(target, contains('details='));
+  });
 }