Deploy History and Rollback

planned

Track deploy history with content hashing, diff previews, and one-command rollback

Track deploy history and enable rollback.

Deploy log: .deploy-log.json with timestamp, target, commit hash, build duration, and content hash
Deploy diff: seite deploy--dry-run shows new/modified/deleted files compared to last deploy
Rollback: seite deployrollback restores previous deploy using Netlify/Cloudflare APIs or git history
Atomic deploys: skip deploy if content hash unchanged since last deploy