Both bugs surfaced only on split-role deployments (the MAIN cluster's
admin-only nodes), where the AdminUI runs without the driver role.
- Test Connect returned "No probe registered" for every driver: the
IDriverProbe set was registered only under the driver role, but the
admin-operations singleton that consumes it is pinned to admin. Extract
AddOtOpcUaDriverProbes() (idempotent via TryAddEnumerable) and call it
in the hasAdmin path too.
- Live driver-status/alerts/script-log panels showed "SignalR error:
Connection refused": these Blazor Server components opened a HubConnection
to their own hub via the browser's public URL, which server-side code
can't reach behind Traefik (host :9200 -> container :9000). Read the
in-process source directly instead -- DriverStatus via
IDriverStatusSnapshotStore.SnapshotChanged, Alerts/ScriptLog via a new
IInProcessBroadcaster<T>. Fleet status was unaffected (reads DB/ActorSystem).
Adds unit tests for probe registration, the snapshot-store event, and the
broadcaster.