Adds Security section to appsettings.json with configurable OPC UA
transport profiles (None, Basic256Sha256-Sign, Basic256Sha256-SignAndEncrypt),
certificate policy settings, and a configurable BindAddress for the
OPC UA endpoint. Defaults preserve backward compatibility.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Implements configurable user authentication (anonymous + username/password)
with pluggable credential provider (IUserAuthenticationProvider). Anonymous
writes can be disabled via AnonymousCanWrite setting while reads remain
open. Adds -U/-P flags to all CLI commands for authenticated sessions.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>