feat: improved error handling and redirect on invalid session

templates/booking/create/error.html.twig

@@ -12,7 +12,8 @@
             messages: errorMessages
         } %}
 
-        <a href="{{ returnUrl }}" class="button button--secondary">
+        {# hx-boost disabled for cross-origin #}
+        <a href="{{ returnUrl }}" hx-boost="false" class="button button--secondary">
             Zurück
         </a>
     </div>