purge_stale_alerts used _find_threshold to validate alert state keys,
but _find_threshold has no wildcard matching. A threshold configured as
"zfs_monitor.*.status" never matched the concrete alert state key
"zfs_monitor.tank.status", so every restart silently purged active ZFS
pool alert states and reset the grace period from scratch.
Also fix _check_pending_or_renotify to set last_notification after the
grace-period notification fires, so the re-notification interval is
anchored to when the alert was actually sent rather than the next PLG cycle.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
andreas
aef9e7769b