Clients deleted every auto-backup_ snapshot on the server except the
newest, so the backup held one state only. prune-snapshots now keeps
the newest per day, week and month (14/8/24 by default) independent of
the source, and the clients call it after each receive.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RywMtsL8qXG7GDY3MHq9Uh