format: fix psr12 style issues

phpcbf auto-fixes: string concatenation spacing, single-line class braces, closing brace placement.

backend/app/Controllers/AuthController.php

@@ -20,7 +20,8 @@ class AuthController
         private AuthenticateUser $authenticateUser,
         private CreateSession $createSession,
         private Logout $logout,
-    ) {}
+    ) {
+    }
 
     public function login(
         ServerRequestInterface $request,