Captures the brainstormed design to align OtOpcUa with ScadaLink:
single role-gated binary, Akka.NET cluster with admin/driver roles,
cluster singletons for control plane, per-node actor hierarchy for
OPC UA runtime, dual-endpoint warm redundancy preserved with
ServiceLevel driven by Akka leader, cookie+JWT auth, Traefik routing,
and ScadaLink-style live-edit + deploy model replacing the
draft/publish ConfigGeneration lifecycle.
