feat: migrate packaging and auto updates

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

sidecar/tests/Aryx.AgentHost.Tests/JsonSerializationTests.cs

@@ -0,0 +1,41 @@
+using System.Text.Json;
+using System.Text.Json.Serialization.Metadata;
+using Aryx.AgentHost.Services;
+
+namespace Aryx.AgentHost.Tests;
+
+public sealed class JsonSerializationTests
+{
+    [Fact]
+    public void CreateWebOptions_UsesDefaultJsonTypeInfoResolver()
+    {
+        JsonSerializerOptions options = JsonSerialization.CreateWebOptions();
+
+        Assert.IsType<DefaultJsonTypeInfoResolver>(options.TypeInfoResolver);
+    }
+
+    [Fact]
+    public void CreateWebOptions_RoundTripsRuntimeTypedPayloads()
+    {
+        JsonSerializerOptions options = JsonSerialization.CreateWebOptions();
+        object payload = new TestPayload
+        {
+            Type = "describe-capabilities",
+            RequestId = "req-1",
+        };
+
+        string json = JsonSerializer.Serialize(payload, payload.GetType(), options);
+        TestPayload? deserialized = JsonSerializer.Deserialize<TestPayload>(json, options);
+
+        Assert.NotNull(deserialized);
+        Assert.Equal("describe-capabilities", deserialized.Type);
+        Assert.Equal("req-1", deserialized.RequestId);
+    }
+
+    private sealed class TestPayload
+    {
+        public string? Type { get; init; }
+
+        public string? RequestId { get; init; }
+    }
+}