Persist DigitalOcean, Hetzner, and Vultr servers before public IP
assignment, then backfill placeholder addresses from provider state.
Treat partial Sentinel snapshots as non-authoritative and document the
destinations API with OpenAPI schemas.
Ignore health status changes in Sentinel push deduplication when the container lifecycle state is unchanged.
Scope stale resource checks to Sentinel servers whose heartbeat is stale, and avoid refreshing resource last_online_at on unchanged statuses.