refactor: track import progress per film instead of per batch

Replace batch-level progress (processedBatches/totalBatches) with
film-level progress (processedFilms/totalFilms) for smoother UI updates.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/MessageHandler/ProcessImportMessageHandler.php

@@ -49,10 +49,8 @@ readonly class ProcessImportMessageHandler
             }
 
             $totalFilms = count($ltbxdMovies);
-            $totalBatches = (int) ceil($totalFilms / self::BATCH_SIZE);
 
             $import->setTotalFilms($totalFilms);
-            $import->setTotalBatches($totalBatches);
             $import->setStatus(Import::STATUS_PROCESSING);
             $this->em->flush();