The artifacts endpoint only supports sorting by: created_at, size, original_name
But the frontend was defaulting to 'name' (from the old tags endpoint).
- Change default sort from 'name' to 'created_at'
- Change default order from 'asc' to 'desc' (newest first)
- Remove sortable flag from version/tags columns (not DB fields)
- Add sortable flag to original_name and size columns
f04149b410