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.

src/__Libraries/StellaOps.Router.Common/Models/CancelPayload.cs

@@ -10,3 +10,34 @@ public sealed record CancelPayload
     /// </summary>
     public string? Reason { get; init; }
 }
+
+/// <summary>
+/// Standard reasons for request cancellation.
+/// </summary>
+public static class CancelReasons
+{
+    /// <summary>
+    /// The HTTP client disconnected before the request completed.
+    /// </summary>
+    public const string ClientDisconnected = "ClientDisconnected";
+
+    /// <summary>
+    /// The request exceeded its timeout.
+    /// </summary>
+    public const string Timeout = "Timeout";
+
+    /// <summary>
+    /// The request or response payload exceeded configured limits.
+    /// </summary>
+    public const string PayloadLimitExceeded = "PayloadLimitExceeded";
+
+    /// <summary>
+    /// The gateway or microservice is shutting down.
+    /// </summary>
+    public const string Shutdown = "Shutdown";
+
+    /// <summary>
+    /// The transport connection was closed unexpectedly.
+    /// </summary>
+    public const string ConnectionClosed = "ConnectionClosed";
+}

src/__Libraries/StellaOps.Router.Common/Models/EndpointDescriptor.cs

@@ -39,4 +39,10 @@ public sealed record EndpointDescriptor
     /// Gets a value indicating whether this endpoint supports streaming.
     /// </summary>
     public bool SupportsStreaming { get; init; }
+
+    /// <summary>
+    /// Gets the handler type that processes requests for this endpoint.
+    /// This is used by the Microservice SDK for handler resolution.
+    /// </summary>
+    public Type? HandlerType { get; init; }
 }

src/__Libraries/StellaOps.Router.Common/Models/StreamDataPayload.cs

@@ -0,0 +1,27 @@
+namespace StellaOps.Router.Common.Models;
+
+/// <summary>
+/// Payload for streaming data frames (REQUEST_STREAM_DATA/RESPONSE_STREAM_DATA).
+/// </summary>
+public sealed record StreamDataPayload
+{
+    /// <summary>
+    /// Gets the correlation ID linking stream data to the original request.
+    /// </summary>
+    public required Guid CorrelationId { get; init; }
+
+    /// <summary>
+    /// Gets the stream data chunk.
+    /// </summary>
+    public byte[] Data { get; init; } = [];
+
+    /// <summary>
+    /// Gets a value indicating whether this is the final chunk.
+    /// </summary>
+    public bool EndOfStream { get; init; }
+
+    /// <summary>
+    /// Gets the sequence number for ordering.
+    /// </summary>
+    public int SequenceNumber { get; init; }
+}

src/__Libraries/StellaOps.Router.Common/Models/StreamingOptions.cs

@@ -0,0 +1,36 @@
+namespace StellaOps.Router.Common.Models;
+
+/// <summary>
+/// Configuration options for streaming operations.
+/// </summary>
+public sealed record StreamingOptions
+{
+    /// <summary>
+    /// Gets the default streaming options.
+    /// </summary>
+    public static readonly StreamingOptions Default = new();
+
+    /// <summary>
+    /// Gets the size of each chunk when streaming data.
+    /// Default: 64 KB.
+    /// </summary>
+    public int ChunkSize { get; init; } = 64 * 1024;
+
+    /// <summary>
+    /// Gets the maximum number of concurrent streams per connection.
+    /// Default: 100.
+    /// </summary>
+    public int MaxConcurrentStreams { get; init; } = 100;
+
+    /// <summary>
+    /// Gets the timeout for idle streams (no data flowing).
+    /// Default: 5 minutes.
+    /// </summary>
+    public TimeSpan StreamIdleTimeout { get; init; } = TimeSpan.FromMinutes(5);
+
+    /// <summary>
+    /// Gets the channel capacity for buffered stream data.
+    /// Default: 16 chunks.
+    /// </summary>
+    public int ChannelCapacity { get; init; } = 16;
+}