Scheduled backup and restore

[mohith-das]

Summary

Automated scheduled backups and one-command restore.

Approach

• wikimcp backup --dir /data/wikimcp --out /backups/ — snapshot all user wikis
• wikimcp restore --from /backups/wikimcp-2026-04-14.tar.gz
• Cron-compatible: add to crontab or systemd timer
• Incremental backups via git bundle