fix(messenger): re-broadcast audio message after blob attaches

Messenger ingest saves the Attachment row before attaching the blob, so
the after_create_commit broadcast bails on file.attached? and the FE
never gets the audio bubble until a refresh (or until Whisper finishes,
or never if transcription is disabled or returns blank). Re-fire the
message update after attach completes.

app/builders/messages/messenger/message_builder.rb

@@ -28,6 +28,10 @@ class Messages::Messenger::MessageBuilder
       filename: attachment_file.original_filename,
       content_type: attachment_file.content_type
     )
+    # The Attachment row is saved before the blob is attached, so the
+    # after_create_commit broadcast bails on `file.attached?`. Re-fire here
+    # for audio so the bubble updates without waiting on transcription.
+    attachment.message&.reload&.send_update_event if attachment.file_type.to_sym == :audio
   end
 
   def attachment_params(attachment)