Add unit tests for Router configuration and transport layers

- Implemented tests for RouterConfig, RoutingOptions, StaticInstanceConfig, and RouterConfigOptions to ensure default values are set correctly.
- Added tests for RouterConfigProvider to validate configurations and ensure defaults are returned when no file is specified.
- Created tests for ConfigValidationResult to check success and error scenarios.
- Developed tests for ServiceCollectionExtensions to verify service registration for RouterConfig.
- Introduced UdpTransportTests to validate serialization, connection, request-response, and error handling in UDP transport.
- Added scripts for signing authority gaps and hashing DevPortal SDK snippets.

tests/StellaOps.Microservice.Tests/EndpointDiscoveryServiceTests.cs

@@ -0,0 +1,185 @@
+using FluentAssertions;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+using StellaOps.Microservice;
+using StellaOps.Router.Common.Models;
+using Xunit;
+
+namespace StellaOps.Microservice.Tests;
+
+/// <summary>
+/// Tests for EndpointDiscoveryService - verifies integration of discovery + YAML loading + merging.
+/// </summary>
+public class EndpointDiscoveryServiceTests
+{
+    private readonly Mock<IEndpointDiscoveryProvider> _discoveryProviderMock;
+    private readonly Mock<IMicroserviceYamlLoader> _yamlLoaderMock;
+    private readonly Mock<IEndpointOverrideMerger> _mergerMock;
+    private readonly ILogger<EndpointDiscoveryService> _logger;
+    private readonly EndpointDiscoveryService _service;
+
+    public EndpointDiscoveryServiceTests()
+    {
+        _discoveryProviderMock = new Mock<IEndpointDiscoveryProvider>();
+        _yamlLoaderMock = new Mock<IMicroserviceYamlLoader>();
+        _mergerMock = new Mock<IEndpointOverrideMerger>();
+        _logger = NullLogger<EndpointDiscoveryService>.Instance;
+
+        _service = new EndpointDiscoveryService(
+            _discoveryProviderMock.Object,
+            _yamlLoaderMock.Object,
+            _mergerMock.Object,
+            _logger);
+    }
+
+    [Fact]
+    public void DiscoverEndpoints_CallsDiscoveryProvider()
+    {
+        var codeEndpoints = new List<EndpointDescriptor>();
+        _discoveryProviderMock
+            .Setup(x => x.DiscoverEndpoints())
+            .Returns(codeEndpoints);
+        _mergerMock
+            .Setup(x => x.Merge(It.IsAny<IReadOnlyList<EndpointDescriptor>>(), It.IsAny<MicroserviceYamlConfig?>()))
+            .Returns(codeEndpoints);
+
+        _service.DiscoverEndpoints();
+
+        _discoveryProviderMock.Verify(x => x.DiscoverEndpoints(), Times.Once);
+    }
+
+    [Fact]
+    public void DiscoverEndpoints_CallsYamlLoader()
+    {
+        var codeEndpoints = new List<EndpointDescriptor>();
+        _discoveryProviderMock
+            .Setup(x => x.DiscoverEndpoints())
+            .Returns(codeEndpoints);
+        _mergerMock
+            .Setup(x => x.Merge(It.IsAny<IReadOnlyList<EndpointDescriptor>>(), It.IsAny<MicroserviceYamlConfig?>()))
+            .Returns(codeEndpoints);
+
+        _service.DiscoverEndpoints();
+
+        _yamlLoaderMock.Verify(x => x.Load(), Times.Once);
+    }
+
+    [Fact]
+    public void DiscoverEndpoints_PassesCodeEndpointsAndYamlConfigToMerger()
+    {
+        var codeEndpoints = new List<EndpointDescriptor>
+        {
+            CreateEndpoint("GET", "/api/test")
+        };
+        var yamlConfig = new MicroserviceYamlConfig
+        {
+            Endpoints =
+            [
+                new EndpointOverrideConfig { Method = "GET", Path = "/api/test" }
+            ]
+        };
+
+        _discoveryProviderMock
+            .Setup(x => x.DiscoverEndpoints())
+            .Returns(codeEndpoints);
+        _yamlLoaderMock
+            .Setup(x => x.Load())
+            .Returns(yamlConfig);
+        _mergerMock
+            .Setup(x => x.Merge(codeEndpoints, yamlConfig))
+            .Returns(codeEndpoints);
+
+        _service.DiscoverEndpoints();
+
+        _mergerMock.Verify(x => x.Merge(codeEndpoints, yamlConfig), Times.Once);
+    }
+
+    [Fact]
+    public void DiscoverEndpoints_ReturnsMergedEndpoints()
+    {
+        var codeEndpoints = new List<EndpointDescriptor>
+        {
+            CreateEndpoint("GET", "/api/test", TimeSpan.FromSeconds(10))
+        };
+        var mergedEndpoints = new List<EndpointDescriptor>
+        {
+            CreateEndpoint("GET", "/api/test", TimeSpan.FromMinutes(5))
+        };
+
+        _discoveryProviderMock
+            .Setup(x => x.DiscoverEndpoints())
+            .Returns(codeEndpoints);
+        _mergerMock
+            .Setup(x => x.Merge(It.IsAny<IReadOnlyList<EndpointDescriptor>>(), It.IsAny<MicroserviceYamlConfig?>()))
+            .Returns(mergedEndpoints);
+
+        var result = _service.DiscoverEndpoints();
+
+        result.Should().BeSameAs(mergedEndpoints);
+    }
+
+    [Fact]
+    public void DiscoverEndpoints_ContinuesWithNullYamlConfig_WhenLoaderReturnsNull()
+    {
+        var codeEndpoints = new List<EndpointDescriptor>
+        {
+            CreateEndpoint("GET", "/api/test")
+        };
+
+        _discoveryProviderMock
+            .Setup(x => x.DiscoverEndpoints())
+            .Returns(codeEndpoints);
+        _yamlLoaderMock
+            .Setup(x => x.Load())
+            .Returns((MicroserviceYamlConfig?)null);
+        _mergerMock
+            .Setup(x => x.Merge(codeEndpoints, null))
+            .Returns(codeEndpoints);
+
+        var result = _service.DiscoverEndpoints();
+
+        _mergerMock.Verify(x => x.Merge(codeEndpoints, null), Times.Once);
+        result.Should().BeSameAs(codeEndpoints);
+    }
+
+    [Fact]
+    public void DiscoverEndpoints_ContinuesWithNullYamlConfig_WhenLoaderThrows()
+    {
+        var codeEndpoints = new List<EndpointDescriptor>
+        {
+            CreateEndpoint("GET", "/api/test")
+        };
+
+        _discoveryProviderMock
+            .Setup(x => x.DiscoverEndpoints())
+            .Returns(codeEndpoints);
+        _yamlLoaderMock
+            .Setup(x => x.Load())
+            .Throws(new Exception("YAML parsing failed"));
+        _mergerMock
+            .Setup(x => x.Merge(codeEndpoints, null))
+            .Returns(codeEndpoints);
+
+        var result = _service.DiscoverEndpoints();
+
+        // Should not throw, should continue with null config
+        _mergerMock.Verify(x => x.Merge(codeEndpoints, null), Times.Once);
+        result.Should().BeSameAs(codeEndpoints);
+    }
+
+    private static EndpointDescriptor CreateEndpoint(
+        string method,
+        string path,
+        TimeSpan? timeout = null)
+    {
+        return new EndpointDescriptor
+        {
+            ServiceName = "test-service",
+            Version = "1.0.0",
+            Method = method,
+            Path = path,
+            DefaultTimeout = timeout ?? TimeSpan.FromSeconds(30)
+        };
+    }
+}