feat: inform user about automatic reassignments or reset selections

templates/booking/create_step_2.html.twig

@@ -52,6 +52,7 @@
 
 {% block content %}
     {% include '_partials/_flashes.html.twig' %}
+    <div {{ stimulus_controller('toast') }}></div>
     <h1>Neue Buchung</h1>
     <div class="grid grid-cols-3 gap-8">
         <div class="col-span-2">