Watches configured channels for image attachments, reposts each image (with
attribution and message text) into a staff-only vault channel, then deletes
the original. Retrieval re-fetches the vault message fresh each time so
there's no stale-link problem, and spoiler tags round-trip intact. Access
to config is admin-only; retrieval defaults to open for everyone.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
