displayed filename in editor does not update on publish

When publishing a post, the `onPublish` should trigger a refresh of the filename displayed in the editor so that it updates from being in `_drafts` to `_posts`.

Start by locating the editor's onPublish handler and the code that displays the filename. Trace how publishing moves a post from _drafts to _posts and identify where the displayed filename is refreshed. Done means publishing updates the editor's filename from the _drafts path to the _posts path.

Written by the indexing model from the issue text.