fix: apply correct return type and response handling

src/BusProNet/Model/RegistrationResponse.php

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\BusProNet\Model;
+
+class RegistrationResponse
+{
+    public function __construct(
+        public readonly int $addressId,
+        public readonly int $personId,
+        public readonly bool $isNewRecord,
+    ) {
+    }
+}