Follow-up to #43: ICNF-only fires flicker while ANEPC is fresh; anepc:sync skips cleanup #45

Codex review on #43:

1. While ANEPC is fresh, CheckIsActive deactivates ICNF-only incidents absent from the ANEPC list and ProcessICNFNewFireData reactivates them on its next run, so they keep disappearing and reappearing.
2. The stale guard in CheckIsActive uses the ArcGIS feed health for every caller, so ProcessANPCAllDataV2 (anepc:sync) never deactivates absent incidents while the ArcGIS feed is stale.