feat(kpi): K7 — SiteCallAudit sample source

src/ZB.MOM.WW.ScadaBridge.SiteCallAudit/ServiceCollectionExtensions.cs

@@ -1,4 +1,6 @@
 using Microsoft.Extensions.DependencyInjection;
+using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Kpi;
+using ZB.MOM.WW.ScadaBridge.SiteCallAudit.Kpi;
 
 namespace ZB.MOM.WW.ScadaBridge.SiteCallAudit;
 
@@ -37,6 +39,13 @@ public static class ServiceCollectionExtensions
         services.AddOptions<SiteCallAuditOptions>()
             .BindConfiguration(OptionsSection);
 
+        // M6 KPI History (#K7): the central recorder enumerates every registered
+        // IKpiSampleSource each sampling pass; this one snapshots the SiteCalls
+        // KPIs (global + per-site + per-node) into the KpiSample history store.
+        // Scoped so each pass resolves a fresh ISiteCallAuditRepository scope,
+        // mirroring the actor's scope-per-message repository access.
+        services.AddScoped<IKpiSampleSource, SiteCallAuditKpiSampleSource>();
+
         return services;
     }
 }