feat(curator): prune built-in skills after inactivity + track usage for all skills (#36701)

Two related changes to the skill curator:

1. Built-in pruning. New curator.prune_builtins config (default on) lets the
   curator archive bundled built-in skills after the inactivity period, not
   just agent-created ones. A .curator_suppressed list tells the update-time
   re-seeder (tools/skills_sync) to leave pruned built-ins archived, so the
   prune is durable across `hermes update`. Built-ins are seeded with a
   baseline record on first sight, so the inactivity clock starts at upgrade
   time -- no mass-prune on the first run. Hub-installed skills are never
   pruned regardless of the flag. Restoring a built-in clears its suppression.

2. Usage tracking for all skills. Telemetry (view/use/patch) was wrongly gated
   behind curation-eligibility, so built-ins were tracked only when prunable
   and hub skills never. Telemetry is observability and is now decoupled from
   curation: every skill accrues usage counts regardless of provenance, while
   lifecycle mutators (set_state/set_pinned/mark_agent_created) stay
   curation-gated. New usage_report() + provenance() expose all skills with an
   agent/bundled/hub tag.

hermes_cli/config.py

@@ -1648,6 +1648,17 @@ DEFAULT_CONFIG = {
         # Archive a skill (move to skills/.archive/) after this many days
         # without use. Archived skills are recoverable — no auto-deletion.
         "archive_after_days": 90,
+        # Also prune (archive) bundled built-in skills after the inactivity
+        # period, not just agent-created ones. ON by default. Built-ins are
+        # normally restored on every `hermes update`, so pruning them only
+        # sticks because a suppression list tells the re-seeder to leave them
+        # archived. Hub-installed skills are NEVER pruned here — they have an
+        # external upstream owner. Built-ins accrue usage telemetry and their
+        # inactivity clock starts the first time the curator sees them, so a
+        # long-unused built-in is archived only after archive_after_days of
+        # genuine non-use (never a mass-prune on the first run). Set to false
+        # to keep all bundled built-ins permanently.
+        "prune_builtins": True,
         # Pre-run backup: before every real curator pass (dry-run is
         # skipped), snapshot ~/.hermes/skills/ into
         # ~/.hermes/skills/.curator_backups/<utc-iso>/skills.tar.gz so the