feat(http): ArenaTwoPickController (6 actions)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

SVSim.UnitTests/Controllers/ArenaTwoPickControllerTests.cs

@@ -0,0 +1,29 @@
+using System.Net;
+using System.Net.Http.Json;
+using SVSim.UnitTests.Infrastructure;
+
+namespace SVSim.UnitTests.Controllers;
+
+public class ArenaTwoPickControllerTests
+{
+    [Test]
+    public async Task Top_unauthenticated_returns_401()
+    {
+        using var factory = new SVSimTestFactory();
+        using var client = factory.CreateClient();
+        var resp = await client.PostAsync("/arena_two_pick/top", JsonContent.Create(new { mode = 0 }));
+        Assert.That(resp.StatusCode, Is.EqualTo(HttpStatusCode.Unauthorized));
+    }
+
+    [Test]
+    public async Task Top_authed_with_no_run_returns_entry_info_null()
+    {
+        using var factory = new SVSimTestFactory();
+        var viewerId = await factory.SeedViewerAsync();
+        using var client = factory.CreateAuthenticatedClient(viewerId);
+        var resp = await client.PostAsync("/arena_two_pick/top", JsonContent.Create(new { mode = 0 }));
+        Assert.That(resp.StatusCode, Is.EqualTo(HttpStatusCode.OK));
+        var body = await resp.Content.ReadAsStringAsync();
+        StringAssert.Contains("\"entry_info\":null", body);
+    }
+}