NC fires one NodeRenamedEvent on a directory rename — children don't
get their own events. The handler bailed on both paths having no
supported extension. Now:
- New `handle_directory_rename(old, new)` in scan.py does a single
transaction of prefix-rewrites against photos.filepath, folders.path,
and source_roots.path. Cross-source-root case (Photos/x → Memories/x)
is treated as discard-the-old-subtree; scan_folder dispatched by the
subsequent NodeWritten/NodeCreated picks up the new root.
- Webhook renamed branch checks "both source and target are
directories" and calls the helper. File renames keep the existing
delete-old + scan-new-parent path.
Idempotent: the SQL matches zero rows the second time around. That
makes the feedback loop safe — mule's existing PATCH /folders/{id}
endpoint already does a WebDAV MOVE + inline DB rewrite for NC paths,
and the resulting NodeRenamedEvent now flows back through this handler
without re-running the rewrite or leaving rows stale.
Trashbin restore (the documented "NC doesn't emit a subscribed event"
gap) is unchanged.