feat: pre-flight check of agency bookings

addresses #869bqxr4q

src/BusProNet/DataProcessor/BookingDataProcessor.php

@@ -15,6 +15,7 @@ use App\Form\Model\ParticipantDto;
 use App\Form\Model\RoomSelectionDto;
 use App\Service\BookingPriceCalculator;
 use App\Service\InsuranceManager;
+use function Symfony\Component\String\u;
 
 /**
  * Processes booking form data and converts it into BusProNet API payload format.
@@ -78,7 +79,7 @@ class BookingDataProcessor
                 // Copy address if first participant has no street (indicating empty/incomplete address)
                 $isEmpty = null === $participantData->address
                     || null === $participantData->address->street
-                    || '' === trim($participantData->address->street);
+                    || u($participantData->address->street)->trim()->isEmpty();
 
                 if ($isEmpty) {
                     $participantData->address = clone $booking->applicant->address;
@@ -155,6 +156,9 @@ class BookingDataProcessor
             // Enrich services with data from travel (especially prices)
             $this->enrichParticipantServicesFromTravel($participantData, $travel);
 
+            // Normalize loaded participant data so the edit flow sees canonical values.
+            $participantData->normalizeLoadedData();
+
             $dto->participants[$index] = $participantData;
         }