feat(options): eager startup validation for central-component options (Transport, SiteCallAudit, DeploymentManager) (arch-review 08 §1.5)

Claude-Session: https://claude.ai/code/session_01MtdgwpEeCUn6cUA5f1LMPj

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

@@ -1,5 +1,6 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.Extensions.Options;
 using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Kpi;
 using ZB.MOM.WW.ScadaBridge.SiteCallAudit.Kpi;
 
@@ -37,8 +38,15 @@ public static class ServiceCollectionExtensions
     {
         ArgumentNullException.ThrowIfNull(services);
 
+        // Eager startup validation (arch-review 08 §1.5): ValidateOnStart makes a
+        // bad ScadaBridge:SiteCallAudit section — a zero/negative cadence that would
+        // spin an Akka scheduler, or a non-positive KPI/retention knob — fail fast
+        // at boot with a clear, key-naming message.
         services.AddOptions<SiteCallAuditOptions>()
-            .BindConfiguration(OptionsSection);
+            .BindConfiguration(OptionsSection)
+            .ValidateOnStart();
+        services.TryAddEnumerable(
+            ServiceDescriptor.Singleton<IValidateOptions<SiteCallAuditOptions>, SiteCallAuditOptionsValidator>());
 
         // KPI History: the central recorder enumerates every registered
         // IKpiSampleSource each sampling pass; this one snapshots the SiteCalls