Deleting Scribbles

There should be a way to delete a scribble which would restore the default scribble text. Needs to be clear to the user that this is what will happen.

Start by inspecting the Django app's existing scribble management and editing flow, since the issue names no files or tests. Identify where deletion is handled and how default scribble text is stored or restored. Done means users can delete a scribble, understand that deletion restores its default text, and see that behavior consistently.

Written by the indexing model from the issue text.