fix: omit zero-amount surcharges from the booking summary

src/Service/BookingPricingAssembler.php

@@ -102,6 +102,11 @@ class BookingPricingAssembler
         $surchargePricing = [];
 
         foreach ($bookingData->surcharges as $surcharge) {
+            // BusPro reports a Zuschlag line even when it nets to nothing, e.g. Stornokosten of 0,00 €
+            if (0.0 === round($surcharge->totalPrice ?? 0.0, 2)) {
+                continue;
+            }
+
             $surchargePricing[] = [
                 'label' => $surcharge->label ?? 'unbekannt',
                 'participantCount' => count($surcharge->mapping),