feat(ui): complete Avalonia UI port with 7 main pages, tool settings & top MenuBar

tests/ClawdDotNet.Core.Tests/Deploymentcenter/CapturingHandler.cs

@@ -0,0 +1,32 @@
+using System.Net;
+using System.Text;
+
+namespace ClawdDotNet.Core.Tests.Deploymentcenter;
+
+/// <summary>Fängt die letzte Anfrage ab und antwortet fest, ohne Netzwerkzugriff.</summary>
+internal sealed class CapturingHandler(
+    HttpStatusCode status = HttpStatusCode.OK,
+    string responseBody = """{"status":"success"}""")
+    : HttpMessageHandler
+{
+    public HttpRequestMessage? LastRequest { get; private set; }
+
+    public string? LastBody { get; private set; }
+
+    public int Calls { get; private set; }
+
+    protected override async Task<HttpResponseMessage> SendAsync(
+        HttpRequestMessage request, CancellationToken cancellationToken)
+    {
+        Calls++;
+        LastRequest = request;
+
+        if (request.Content is not null)
+            LastBody = await request.Content.ReadAsStringAsync(cancellationToken);
+
+        return new HttpResponseMessage(status)
+        {
+            Content = new StringContent(responseBody, Encoding.UTF8, "application/json")
+        };
+    }
+}