fix(curator): defer first run and add --dry-run preview (#18373) (#18389)

* fix(curator): defer first run and add --dry-run preview (#18373)

Curator was meant to run 7 days after install, not on the very first
gateway tick. On a fresh install (no .curator_state), should_run_now()
returned True immediately because last_run_at was None — so the gateway
cron ticker fired Curator against a fresh skill library moments after
'hermes update'. Combined with the binary 'agent-created' provenance
model (anything not bundled and not hub-installed), this consolidated
hand-authored user workflow skills without consent.

Changes:
- should_run_now(): first observation seeds last_run_at='now' and returns
  False. The next real pass fires one full interval_hours later (7 days
  by default), matching the original design intent.
- hermes curator run --dry-run: produces the same review report without
  applying automatic transitions OR permitting the LLM to call
  skill_manage / terminal mv. A DRY-RUN banner is prepended to the
  prompt and the caller skips apply_automatic_transitions. State is
  NOT advanced so a preview doesn't defer the next scheduled real pass.
- hermes update: prints a one-liner on fresh installs pointing at
  --dry-run, pause, and the docs. Silent on steady state.
- Docs: curator.md and cli-commands.md explain the deferred first-run
  behavior and warn that hand-written SKILL.md files share the
  'agent-created' bucket, with guidance to pin or preview before the
  first pass.

Tests:
- test_first_run_defers replaces the old 'first run always eligible'
  assertion — same fixture, inverted expectation.
- test_maybe_run_curator_defers_on_fresh_install covers the gateway tick
  path end-to-end.
- Three new dry-run tests cover state-advance suppression, prompt
  banner injection, and apply_automatic_transitions skipping.

Fixes #18373.

* feat(curator): pre-run backup + rollback (#18373)

Every real curator pass now snapshots ~/.hermes/skills/ into
~/.hermes/skills/.curator_backups/<utc-iso>/skills.tar.gz before calling
apply_automatic_transitions or the LLM review. If a run consolidates or
archives something the user didn't want touched, 'hermes curator
rollback' restores the tree in one command. Dry-run is skipped — no
mutation means no snapshot needed.

Changes:
- agent/curator_backup.py (new): tar.gz snapshot + safe rollback. The
  snapshot excludes .curator_backups/ (would recurse) and .hub/ (managed
  by the skills hub). Extract refuses absolute paths and .. components,
  and uses tarfile's filter='data' on Python 3.12+. Rollback takes a
  pre-rollback safety snapshot FIRST, stages the current tree into
  .rollback-staging-<ts>/ so the extract lands in an empty dir, and
  cleans the staging dir on success. A failed extract restores the
  staged contents.
- agent/curator.py: run_curator_review() calls curator_backup.
  snapshot_skills(reason='pre-curator-run') before apply_automatic_
  transitions. Best-effort — a failed snapshot logs at debug and the
  run continues (a transient disk issue shouldn't silently disable
  curator forever).
- hermes_cli/curator.py: new 'hermes curator backup' and 'hermes curator
  rollback' subcommands. rollback supports --list, --id <ts>, -y.
- hermes_cli/config.py: curator.backup.{enabled, keep} config block
  with sane defaults (enabled=true, keep=5).
- Docs: curator.md gets a 'Backups and rollback' section; cli-commands
  .md table gets the new rows.

Tests (new file tests/agent/test_curator_backup.py, 16 cases):
- snapshot creates tarball + manifest with correct counts
- snapshot excludes .curator_backups/ (recursion guard) and .hub/
- snapshot disabled via config returns None without creating anything
- snapshot uniquifies ids within the same second (-01 suffix)
- prune honors keep count, newest-first
- list_backups + _resolve_backup cover newest-default and unknown-id
- rollback restores a deleted skill with content intact
- rollback is itself undoable — safety snapshot shows up in list_backups
- rollback with no snapshots returns an error
- rollback refuses tarballs with absolute paths or .. components
- real curator runs take a 'pre-curator-run' snapshot; dry-runs do not

All curator tests: 210 passing locally.

website/docs/reference/cli-commands.md

@@ -718,12 +718,21 @@ The curator is an auxiliary-model background task that periodically reviews agen
 |------------|-------------|
 | `status` | Show curator status and skill stats |
 | `run` | Trigger a curator review now |
+| `run --sync` | Block until the LLM pass finishes |
+| `run --dry-run` | Preview only — produce the review report with no mutations |
+| `backup` | Take a manual tar.gz snapshot of `~/.hermes/skills/` (curator also snapshots automatically before every real run) |
+| `rollback` | Restore `~/.hermes/skills/` from a snapshot (defaults to newest) |
+| `rollback --list` | List available snapshots |
+| `rollback --id <ts>` | Restore a specific snapshot by id |
+| `rollback -y` | Skip the confirmation prompt |
 | `pause` | Pause the curator until resumed |
 | `resume` | Resume a paused curator |
 | `pin <skill>` | Pin a skill so the curator never auto-transitions it |
 | `unpin <skill>` | Unpin a skill |
 | `restore <skill>` | Restore an archived skill |
 
+On a fresh install the first scheduled pass is deferred by one full `interval_hours` (7 days by default) — the gateway will not curate immediately on the first tick after `hermes update`. Use `hermes curator run --dry-run` to preview before that happens.
+
 See [Curator](../user-guide/features/curator.md) for behavior and config.
 
 ## `hermes fallback`