feat(tutorial): add /tutorial/gift_top with hardcoded starter present list

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

SVSim.UnitTests/Controllers/GiftControllerTests.cs

@@ -0,0 +1,50 @@
+using System.Net;
+using System.Text;
+using System.Text.Json;
+using NUnit.Framework;
+using SVSim.UnitTests.Infrastructure;
+
+namespace SVSim.UnitTests.Controllers;
+
+public class GiftControllerTests
+{
+    private const string BaseAuthBlock =
+        @"""viewer_id"":""0"",""steam_id"":0,""steam_session_ticket"":""""";
+
+    [Test]
+    public async Task GiftTop_returns_five_tutorial_gifts_for_unclaimed_viewer()
+    {
+        using var factory = new SVSimTestFactory();
+        long viewerId = await factory.SeedViewerAsync(tutorialState: 31);
+        using var client = factory.CreateAuthenticatedClient(viewerId);
+
+        var response = await client.PostAsync("/tutorial/gift_top",
+            new StringContent($$"""{"page":1,{{BaseAuthBlock}}}""", Encoding.UTF8, "application/json"));
+
+        Assert.That(response.StatusCode, Is.EqualTo(HttpStatusCode.OK));
+        using var doc = JsonDocument.Parse(await response.Content.ReadAsStringAsync());
+        var root = doc.RootElement;
+
+        var presents = root.GetProperty("present_list");
+        Assert.That(presents.GetArrayLength(), Is.EqualTo(5));
+
+        // Expect the legendary pack entry (present_id 71478630) to be present.
+        bool foundLegendaryGift = false;
+        foreach (var p in presents.EnumerateArray())
+        {
+            if (p.GetProperty("present_id").GetString() == "71478630")
+            {
+                foundLegendaryGift = true;
+                Assert.That(p.GetProperty("reward_type").GetString(), Is.EqualTo("4"));
+                Assert.That(p.GetProperty("reward_detail_id").GetString(), Is.EqualTo("90001"));
+                Assert.That(p.GetProperty("reward_count").GetString(), Is.EqualTo("1"));
+                Assert.That(p.GetProperty("item_type").GetInt32(), Is.EqualTo(2));
+                Assert.That(p.GetProperty("message").GetString(), Is.EqualTo("For completing the tutorial"));
+            }
+        }
+        Assert.That(foundLegendaryGift, Is.True, "Legendary starter pack gift (71478630) must be in present_list.");
+
+        Assert.That(root.GetProperty("present_history_list").GetArrayLength(), Is.EqualTo(0));
+        Assert.That(root.GetProperty("limit_over_present_list").GetArrayLength(), Is.EqualTo(0));
+    }
+}