add comments

src/Controller/HistoryController.php

@@ -24,11 +24,11 @@ use Symfony\Component\Routing\Annotation\Route;
  * - Client identity is resolved exclusively via ClientIdResolver
  * - No user identifiers are accepted from the request
  */
-final class HistoryController
+final readonly class HistoryController
 {
     public function __construct(
-        private readonly ContextService $contextService,
-        private readonly ClientIdResolver $clientIdResolver,
+        private ContextService   $contextService,
+        private ClientIdResolver $clientIdResolver,
     ) {}
 
     /**