Add test for /connection/sso/check route to cover OAuthController 100%

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/Controller/OAuthControllerTest.php

@@ -22,4 +22,13 @@ class OAuthControllerTest extends WebTestCase
 
         self::assertResponseRedirects('/');
     }
+
+    public function testSsoCheckRedirectsToLogin(): void
+    {
+        $client = static::createClient();
+        $client->request('GET', '/connection/sso/check');
+
+        // Without OAuth token, the authenticator redirects to login
+        self::assertResponseRedirects();
+    }
 }