Introduces the IAuditActorAccessor seam and HttpAuditActorAccessor impl so the
ZB.MOM.WW.Audit.AuditEvent Actor field can be sourced from the authenticated Blazor
cookie principal (ZbClaimTypes.Username) when structured emitters are added. Adds the
AuditActor.Resolve static helper (accessor value → SystemFallback/"system") as the
canonical pattern for future emit sites. Wires DI in AddOtOpcUaAuth (TryAddScoped) with
AddHttpContextAccessor(). The structured AuditEvent path remains DORMANT — no live emit
sites exist; seam is forward-looking. SP-based audit path left untouched. 9 new unit
tests all green; Security (54) and ControlPlane (45) test suites fully pass.
Joseph Doherty