Add determinism tests for verdict artifact generation and update SHA256 sums script

- Implemented comprehensive tests for verdict artifact generation to ensure deterministic outputs across various scenarios, including identical inputs, parallel execution, and change ordering.
- Created helper methods for generating sample verdict inputs and computing canonical hashes.
- Added tests to validate the stability of canonical hashes, proof spine ordering, and summary statistics.
- Introduced a new PowerShell script to update SHA256 sums for files, ensuring accurate hash generation and file integrity checks.

src/Excititor/StellaOps.Excititor.WebService/Program.cs

@@ -41,6 +41,7 @@ using StellaOps.Excititor.WebService.Contracts;
 using System.Globalization;
 using StellaOps.Excititor.WebService.Graph;
 using StellaOps.Excititor.Core.Storage;
+using StellaOps.Router.AspNet;
 
 var builder = WebApplication.CreateBuilder(args);
 var configuration = builder.Configuration;
@@ -165,10 +166,18 @@ services.AddAuthorization();
 
 builder.ConfigureExcititorTelemetry();
 
+// Stella Router integration
+var routerOptions = configuration.GetSection("Excititor:Router").Get<StellaRouterOptionsBase>();
+services.TryAddStellaRouter(
+    serviceName: "excititor",
+    version: typeof(Program).Assembly.GetName().Version?.ToString() ?? "1.0.0",
+    routerOptions: routerOptions);
+
 var app = builder.Build();
 
 app.UseAuthentication();
 app.UseAuthorization();
+app.TryUseStellaRouter(routerOptions);
 app.UseObservabilityHeaders();
 
 app.MapGet("/excititor/status", async (HttpContext context,
@@ -2241,6 +2250,9 @@ LinksetEndpoints.MapLinksetEndpoints(app);
 // Risk Feed APIs (EXCITITOR-RISK-66-001)
 RiskFeedEndpoints.MapRiskFeedEndpoints(app);
 
+// Refresh Router endpoint cache
+app.TryRefreshStellaRouterEndpoints(routerOptions);
+
 app.Run();
 
 internal sealed record ExcititorTimelineEvent(