pristine-sweep-blind-to-its-own-enforcement-artifacts

The initial Pristine Sweep checked content hygiene (stale refs, bloat, format contracts) but never verified whether its own enforcement mechanism was intact. If any of the 6 enforcement artifacts (guard hook, marker hook, settings.json registrations, hookify files, sweep cron, sweep script) were deleted, nothing would detect the gap. Added check_enforcement_integrity() function to the sweep that verifies all 6 artifacts exist and JSON remains valid.