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.DeploymentManager/ServiceCollectionExtensions.cs

@@ -1,4 +1,6 @@
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.Extensions.Options;
 using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Transport;
 
 namespace ZB.MOM.WW.ScadaBridge.DeploymentManager;
@@ -27,8 +29,14 @@ public static class ServiceCollectionExtensions
     {
         // Ensure the options class is always resolvable.
         // The Host binds OptionsSection to appsettings.json; absent that binding
-        // the declared option-class defaults apply.
-        services.AddOptions<DeploymentManagerOptions>();
+        // the declared option-class defaults apply. Eager startup validation
+        // (arch-review 08 §1.5): ValidateOnStart makes a zero/negative timeout —
+        // which would fire a linked-CTS deadline immediately (or throw in the
+        // CancellationTokenSource ctor) — fail fast at boot with a clear,
+        // key-naming message. Applies even though defaults are code-configured.
+        services.AddOptions<DeploymentManagerOptions>().ValidateOnStart();
+        services.TryAddEnumerable(
+            ServiceDescriptor.Singleton<IValidateOptions<DeploymentManagerOptions>, DeploymentManagerOptionsValidator>());
         services.AddSingleton<OperationLockManager>();
 
         // Push-based deployment-status notification. Registered