Fix: place consumed files before running the post-consume script

The consumer's storage phase opens its own file move scope, which nests under the consume task's scope. Moves requested while storing the document therefore stayed pending until the task ended, and the post-consume script could be handed a path from before the move.

The consumer now flushes the pending file moves once after the storage block, outside the media lock and the transaction, and before the post-consume script runs.

src/documents/consumer.py

@@ -27,6 +27,7 @@ from documents.file_handling import generate_filename
 from documents.file_handling import generate_unique_filename
 from documents.file_handling import validate_path_in_root
 from documents.file_moves import defer_file_moves
+from documents.file_moves import flush_pending_file_moves
 from documents.loggers import LoggingMixin
 from documents.media_lock import media_lock
 from documents.models import Correspondent
@@ -810,6 +811,10 @@ class ConsumerPlugin(
                         exception=e,
                     )
 
+        # The storage scope above nests under the consume task's scope, so its
+        # moves are still pending; place the file before the script reads its path.
+        flush_pending_file_moves()
+
         self.run_post_consume_script(document)
 
         self.log.info(f"Document {document} consumption finished")