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.

examples/router/src/Examples.Inventory.Microservice/Endpoints/GetItemEndpoint.cs

@@ -0,0 +1,64 @@
+using Microsoft.Extensions.Logging;
+using StellaOps.Microservice;
+
+namespace Examples.Inventory.Microservice.Endpoints;
+
+/// <summary>
+/// Request model for getting a single inventory item.
+/// </summary>
+public sealed record GetItemRequest
+{
+    public required string Sku { get; init; }
+}
+
+/// <summary>
+/// Response model for a single inventory item with details.
+/// </summary>
+public sealed record GetItemResponse
+{
+    public required string Sku { get; init; }
+    public required string Name { get; init; }
+    public required string Description { get; init; }
+    public required string Category { get; init; }
+    public required int QuantityOnHand { get; init; }
+    public required int ReorderPoint { get; init; }
+    public required decimal UnitPrice { get; init; }
+    public required string Location { get; init; }
+    public required DateTime LastUpdated { get; init; }
+}
+
+/// <summary>
+/// Endpoint for getting a single inventory item by SKU.
+/// Demonstrates path parameter extraction.
+/// </summary>
+[StellaEndpoint("GET", "/items/{sku}", TimeoutSeconds = 10)]
+public sealed class GetItemEndpoint : IStellaEndpoint<GetItemRequest, GetItemResponse>
+{
+    private readonly ILogger<GetItemEndpoint> _logger;
+
+    public GetItemEndpoint(ILogger<GetItemEndpoint> logger)
+    {
+        _logger = logger;
+    }
+
+    public Task<GetItemResponse> HandleAsync(
+        GetItemRequest request,
+        CancellationToken cancellationToken)
+    {
+        _logger.LogInformation("Fetching inventory item {Sku}", request.Sku);
+
+        // Simulate item lookup
+        return Task.FromResult(new GetItemResponse
+        {
+            Sku = request.Sku,
+            Name = "Widget A",
+            Description = "A high-quality widget for general purpose use",
+            Category = "widgets",
+            QuantityOnHand = 100,
+            ReorderPoint = 25,
+            UnitPrice = 9.99m,
+            Location = "Warehouse A, Aisle 3, Shelf 2",
+            LastUpdated = DateTime.UtcNow.AddHours(-2)
+        });
+    }
+}