lit/media-update validates the whole batch first (edit_post, lengths, optional
modified lock) and restores already written items when a write fails midway.
lit/media-delete requires confirm, refuses used media without force and
reports refused deletes as write_failed.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7
