Add ActiveNodeHealthCheck that returns 200 only on the Akka.NET cluster
leader, enabling Traefik to route traffic to the active central node and
automatically fail over when the leader changes. Also fixes AkkaClusterHealthCheck
to resolve ActorSystem from AkkaHostedService (was always null via DI).
Adds a fourth Docker service (Mailpit) to capture outgoing emails without
delivery, with CLI tool for sending test emails, listing/reading captured
messages, and clearing the inbox. Supports BCC pattern matching ScadaLink's
notification delivery model.
Stand up local dev infrastructure (OPC UA, LDAP, MS SQL) with Docker Compose,
Python CLI tools for service interaction, and teardown script. Fix GLAuth config
mount, OPC PLC node format, and document actual DN/namespace behavior discovered
during testing. Resolve Q1-Q8,Q10: .NET 10, Akka.NET 1.5.x, monorepo with slnx,
appsettings JWT, Windows Server 2022 site target.
