Three changes consolidated into the existing backup system:
1. Fix: hermes backup now uses sqlite3.Connection.backup() for .db files
instead of raw file copy. Raw copy of a WAL-mode database can produce
a corrupted backup — the backup() API handles this correctly.
2. hermes backup --quick: fast snapshot of just critical state files
(config.yaml, state.db, .env, auth.json, cron/jobs.json, etc.)
stored in ~/.hermes/state-snapshots/. Auto-prunes to 20 snapshots.
3. /snapshot slash command (alias /snap): in-session interface for
quick state snapshots. create/list/restore/prune subcommands.
Restore by ID or number. Powered by the same backup module.
No new modules — everything lives in hermes_cli/backup.py alongside
the existing full backup/import code.
No hooks in run_agent.py — purely on-demand, zero runtime overhead.
Closes the use case from PRs #8406 and #7813 with ~200 lines of new
logic instead of a 1090-line content-addressed storage engine.