Behavior: Permanently deletes the specified asset. If the asset is a folder,
all child assets within the folder are also deleted. The asset is removed from storage
and the search index.

Authorization: Requires a valid Bearer token.

Side Effects: The asset and its associated files are permanently removed.
For folders, all child assets are recursively deleted.

Error Scenarios: Returns 401 if the caller is not authenticated.
Returns 404 if no asset exists with the specified ID.