b350fba233
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.