e14433cd64
Wire the M6 KPI History recorder into the central composition path: - Program.cs: call services.AddKpiHistory(configuration) on the central-only branch alongside AddNotificationOutbox/AddAuditLog/AddSiteCallAudit. - AkkaHostedService.cs: register KpiHistoryRecorderActor as a central, non-role-scoped ClusterSingletonManager + ClusterSingletonProxy + a PhaseClusterLeave CoordinatedShutdown graceful-stop drain (singleton name 'kpi-history-recorder'), copied/adapted from the audit-log-purge block. - appsettings.Central.json (Host + docker + docker-env2 central nodes): add a ScadaBridge:KpiHistory section (SampleInterval 00:01:00, RetentionDays 90, PurgeInterval 1.00:00:00, DefaultMaxSeriesPoints 200). KPI history is observability/best-effort and MUST NOT gate readiness: the recorder is deliberately NOT added to RequiredSingletonsHealthCheck or any other readiness gate.