fix: correctly calculate room pricing based on participant assignment

src/Service/RoomPricingCalculator.php

@@ -77,16 +77,17 @@ class RoomPricingCalculator
             return $roomPricing;
         }
 
+        $assignmentCounts = $bookingDto->getRoomAssignmentCounts();
+
         foreach ($selectedRooms as $roomSelection) {
             $room = $this->getRoomById($bookingDto, $roomSelection->id);
             if (null === $room || null === $room->price) {
                 continue;
             }
 
-            // Pricing in create flow is based on selected room quantity from step 1.
-            // Do not derive billable units from minPax, which represents capacity constraints.
-            $participantCount = $roomSelection->quantity;
-            $totalPrice = $roomSelection->quantity * $room->price;
+            // Pricing in create flow is based on actual participant assignments per room.
+            $participantCount = $assignmentCounts[$room->id] ?? 0;
+            $totalPrice = $participantCount * $room->price;
 
             $roomPricing[] = [
                 'roomId' => $room->id,