format: fix psr12 style issues

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

backend/app/Auth/UseCases/CreateSession/CreateSession.php

@@ -17,7 +17,8 @@ class CreateSession
         private SessionRepository $sessionRepo,
         private TokenGenerator $tokenGenerator,
         private Clock $clock,
-    ) {}
+    ) {
+    }
 
     public function execute(User $user): Session
     {