feat: automatically assign rooms only for unique room type selection

src/Service/ParticipantCardDataService.php

@@ -103,6 +103,9 @@ class ParticipantCardDataService
 
     /**
      * Calculate and format individual participant price.
+     *
+     * Returns a dash (-) when the price is zero and no room is assigned,
+     * indicating incomplete configuration rather than a zero-cost booking.
      */
     private function getFormattedPrice(BookingDto $bookingDto, int $index): string
     {
@@ -110,6 +113,12 @@ class ParticipantCardDataService
 
         $price = $prices[$index] ?? 0.0;
 
+        // Display dash when price is zero and no room assigned (incomplete configuration)
+        $participant = $bookingDto->participants[$index] ?? null;
+        if (0.0 === $price && (null === $participant || null === $participant->assignedRoomId)) {
+            return '-';
+        }
+
         return number_format($price, 2, ',', '.').' €';
     }
 }