feat: initialize KwisatzHaderach .NET web application

src/backend/KwisatzHaderach/Infrastructure/Api/ILLMClient.cs

@@ -0,0 +1,10 @@
+using KwisatzHaderach.Models;
+using Refit;
+
+namespace KwisatzHaderach.Infrastructure.Api;
+
+public interface ILLMClient
+{
+    [Post("/ask-stream")]
+    Task<HttpResponseMessage> GetPromptResponseAsync([Body]PromptRequest req, CancellationToken cancellationToken);
+}