Implement InMemory Transport Layer for StellaOps Router

- Added InMemoryTransportOptions class for configuration settings including timeouts and latency.
- Developed InMemoryTransportServer class to handle connections, frame processing, and event management.
- Created ServiceCollectionExtensions for easy registration of InMemory transport services.
- Established project structure and dependencies for InMemory transport library.
- Implemented comprehensive unit tests for endpoint discovery, connection management, request/response flow, and streaming capabilities.
- Ensured proper handling of cancellation, heartbeat, and hello frames within the transport layer.

src/__Libraries/StellaOps.Router.Common/Abstractions/IGlobalRoutingState.cs

@@ -0,0 +1,31 @@
+using StellaOps.Router.Common.Models;
+
+namespace StellaOps.Router.Common.Abstractions;
+
+/// <summary>
+/// Provides global routing state derived from all live connections.
+/// </summary>
+public interface IGlobalRoutingState
+{
+    /// <summary>
+    /// Resolves an HTTP request to an endpoint descriptor.
+    /// </summary>
+    /// <param name="method">The HTTP method.</param>
+    /// <param name="path">The request path.</param>
+    /// <returns>The endpoint descriptor, or null if not found.</returns>
+    EndpointDescriptor? ResolveEndpoint(string method, string path);
+
+    /// <summary>
+    /// Gets all connections that can handle the specified endpoint.
+    /// </summary>
+    /// <param name="serviceName">The service name.</param>
+    /// <param name="version">The service version.</param>
+    /// <param name="method">The HTTP method.</param>
+    /// <param name="path">The request path.</param>
+    /// <returns>The available connection states.</returns>
+    IReadOnlyList<ConnectionState> GetConnectionsFor(
+        string serviceName,
+        string version,
+        string method,
+        string path);
+}