LocalDbReplicationHealthCheck reports Healthy when replication is default-OFF or
LocalDb is absent (admin-only graphs) - so a plain node is never degraded by it -
Degraded when configured-but-disconnected, connected-with-unknown-backlog (a failed
oplog poll must not read as zero), or connected-with-backlog past the threshold.
Never Unhealthy: a replication fault does not stop the node serving its address
space. Pure decision core is table-tested; registered unconditionally via a factory
so AddOtOpcUaHealth keeps its no-arg signature and resolves ISyncStatus optionally.
Adds LocalDbMetrics.MeterName to the observability allowlist. o.Meters is a strict
allowlist with no wildcard, so the localdb.sync.* / localdb.oplog.depth series were
otherwise silently absent from /metrics - the omission a ScadaBridge live gate
caught.
Joseph Doherty