Add unit tests for RabbitMq and Udp transport servers and clients

- Implemented comprehensive unit tests for RabbitMqTransportServer, covering constructor, disposal, connection management, event handlers, and exception handling.
- Added configuration tests for RabbitMqTransportServer to validate SSL, durable queues, auto-recovery, and custom virtual host options.
- Created unit tests for UdpFrameProtocol, including frame parsing and serialization, header size validation, and round-trip data preservation.
- Developed tests for UdpTransportClient, focusing on connection handling, event subscriptions, and exception scenarios.
- Established tests for UdpTransportServer, ensuring proper start/stop behavior, connection state management, and event handling.
- Included tests for UdpTransportOptions to verify default values and modification capabilities.
- Enhanced service registration tests for Udp transport services in the dependency injection container.

src/Policy/StellaOps.Policy.Engine/Simulation/RiskSimulationService.cs

@@ -1,8 +1,8 @@
 using System.Diagnostics;
-using System.Security.Cryptography;
 using System.Text;
 using System.Text.Json;
 using Microsoft.Extensions.Logging;
+using StellaOps.Cryptography;
 using StellaOps.Policy.Engine.Services;
 using StellaOps.Policy.Engine.Telemetry;
 using StellaOps.Policy.RiskProfile.Hashing;
@@ -19,6 +19,7 @@ public sealed class RiskSimulationService
     private readonly TimeProvider _timeProvider;
     private readonly RiskProfileConfigurationService _profileService;
     private readonly RiskProfileHasher _hasher;
+    private readonly ICryptoHash _cryptoHash;
 
     private static readonly double[] PercentileLevels = { 0.25, 0.50, 0.75, 0.90, 0.95, 0.99 };
     private const int TopMoverCount = 10;
@@ -27,12 +28,14 @@ public sealed class RiskSimulationService
     public RiskSimulationService(
         ILogger<RiskSimulationService> logger,
         TimeProvider timeProvider,
-        RiskProfileConfigurationService profileService)
+        RiskProfileConfigurationService profileService,
+        ICryptoHash cryptoHash)
     {
         _logger = logger ?? throw new ArgumentNullException(nameof(logger));
         _timeProvider = timeProvider ?? throw new ArgumentNullException(nameof(timeProvider));
         _profileService = profileService ?? throw new ArgumentNullException(nameof(profileService));
-        _hasher = new RiskProfileHasher();
+        _cryptoHash = cryptoHash ?? throw new ArgumentNullException(nameof(cryptoHash));
+        _hasher = new RiskProfileHasher(cryptoHash);
     }
 
     /// <summary>
@@ -452,10 +455,10 @@ public sealed class RiskSimulationService
             InformationalCount: scores.Count(s => s.Severity == RiskSeverity.Informational));
     }
 
-    private static string GenerateSimulationId(RiskSimulationRequest request, string profileHash)
+    private string GenerateSimulationId(RiskSimulationRequest request, string profileHash)
     {
         var seed = $"{request.ProfileId}|{profileHash}|{request.Findings.Count}|{Guid.NewGuid()}";
-        var hash = SHA256.HashData(Encoding.UTF8.GetBytes(seed));
-        return $"rsim-{Convert.ToHexStringLower(hash)[..16]}";
+        var hash = _cryptoHash.ComputeHashHexForPurpose(Encoding.UTF8.GetBytes(seed), HashPurpose.Content);
+        return $"rsim-{hash[..16]}";
     }
 }