feat: correct handling of vouchers

templates/booking/_summary.html.twig

@@ -1,6 +1,13 @@
 <div class="booking-summary p-8 bg-gray-50 rounded-lg border sticky top-4">
     <h3 class="font-bold text-xl mb-6 text-gray-800">Buchungsübersicht</h3>
 
+    {# Inquiry booking notification #}
+    {% if bookingCreateDto is defined and bookingCreateDto.isInquiryBooking() %}
+        <div class="mb-4 p-3 bg-yellow-50 border border-yellow-200 rounded text-sm text-yellow-800">
+            <span class="font-semibold">Anfragebuchung:</span> Diese Reise ist ausgebucht. Ihre Buchung wird als Anfrage verarbeitet.
+        </div>
+    {% endif %}
+
     {# Mutability information (edit mode only) #}
     {% if mutableData is defined %}
         <div class="mb-6 pb-4 border-b border-gray-200">