Add StreamableHttpHandler and WithHttpTransport (#291)

* Simplify ModelContextProtocol.AspNetCore README

* Add StreamableHttpHandler

* Use "docker info" in CheckIsDockerAvailable

* Call WithHttpTransport in samples, tests and README

* Cleanup test namespaces

* Add CanConnect_WithMcpClient_AfterCustomizingRoute test

* Simplify relative URI handling

* Handle request made directly to the MapMcp route pattern

* Add Messages_FromNewUser_AreRejected test

* Fix README

* Shorten UserIdClaim ValueTuple names

* Remove MaxReconnectAttempts and ReconnectDelay from SseClientTransportOptions

- Add proper AdditionalHeaders support

tests/ModelContextProtocol.TestSseServer/Program.cs

@@ -412,7 +412,8 @@ public class Program
             builder.Logging.AddProvider(loggerProvider);
         }
 
-        builder.Services.AddMcpServer(ConfigureOptions);
+        builder.Services.AddMcpServer(ConfigureOptions)
+            .WithHttpTransport();
 
         var app = builder.Build();
         app.UseRouting();