Add more tests (#51)

* Add more tests

* Fix some code smells

* Remove more code smells

* Combine "ServerIntegrationTests" and "ClientIntegrationTests" because both are client integration tests just using different servers

* Clean up resources after test

* Improve kill logic for spawned child processes

* Improved testability for Stdio

* Fix SseIntegration tests

tests/mcpdotnet.Tests/Configuration/McpServerBuilderExtensionsTransportsTests.cs

@@ -0,0 +1,23 @@
+using McpDotNet.Configuration;
+using McpDotNet.Protocol.Transport;
+using Microsoft.Extensions.DependencyInjection;
+using Moq;
+
+namespace McpDotNet.Tests.Configuration;
+
+public class McpServerBuilderExtensionsTransportsTests
+{
+    [Fact]
+    public void WithStdioServerTransport_Sets_Transport()
+    {
+        var services = new ServiceCollection();
+        var builder = new Mock<IMcpServerBuilder>();
+        builder.SetupGet(b => b.Services).Returns(services);
+
+        builder.Object.WithStdioServerTransport();
+
+        var transportType = services.FirstOrDefault(s => s.ServiceType == typeof(IServerTransport));
+        Assert.NotNull(transportType);
+        Assert.Equal(typeof(StdioServerTransport), transportType.ImplementationType);
+    }
+}