fix: restore notification dispatch preview formatting

- avoid keyword argument mismatch in push preview label generation

app/notifications/service.py

@@ -72,7 +72,7 @@ async def dispatch_message_notifications(db: AsyncSession, message: Message) ->
     preview_image_url = None
     if first_attachment and first_attachment.file_type.lower().startswith("image/"):
         preview_image_url = first_attachment.file_url
-    preview_body = _message_preview_label(message, preview_image_url=preview_image_url)
+    preview_body = _message_preview_label(message, preview_image_url)
     message_type = message.type.value if hasattr(message.type, "value") else str(message.type)
 
     for recipient in users: