fix: use correct property path for travel date determination

src/Command/DraftBackfillTravelDateCommand.php

@@ -70,7 +70,7 @@ class DraftBackfillTravelDateCommand extends Command
                 continue;
             }
 
-            $travelDate = $bookingData->travel->dateFrom ?? null;
+            $travelDate = $bookingData->travelDate;
 
             if (null === $travelDate) {
                 $io->warning(sprintf('No travel date found for booking %d', $bookingId));