feat(pack): /pack/get_leader_skin_owned_status (empty per-class buckets)

SVSim.EmulatedEntrypoint/Controllers/PackController.cs

@@ -259,6 +259,20 @@ public class PackController : SVSimController
         };
     }
 
+    [HttpPost("get_leader_skin_owned_status")]
+    public ActionResult<Dictionary<string, Dictionary<string, object>>> GetLeaderSkinOwnedStatus(
+        [FromBody] PackGetLeaderSkinOwnedStatusRequest _)
+    {
+        if (!TryGetViewerId(out long __)) return Unauthorized();
+
+        // ClanType range MIN..MAX per spec (CardBasePrm.ClanType). 0..8 inclusive.
+        // Each bucket is `{}` — no curated leader-skin catalog per pack yet.
+        var result = new Dictionary<string, Dictionary<string, object>>(9);
+        for (int classId = 0; classId <= 8; classId++)
+            result[classId.ToString()] = new Dictionary<string, object>();
+        return result;
+    }
+
     [HttpPost("open")]
     [HttpPost("/tutorial/pack_open")]
     public async Task<ActionResult<PackOpenResponse>> Open(PackOpenRequest request)

SVSim.EmulatedEntrypoint/Models/Dtos/Requests/Pack/PackGetLeaderSkinOwnedStatusRequest.cs

@@ -0,0 +1,13 @@
+using MessagePack;
+using System.Text.Json.Serialization;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Requests;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos.Requests.Pack;
+
+[MessagePackObject]
+public class PackGetLeaderSkinOwnedStatusRequest : BaseRequest
+{
+    [JsonPropertyName("parent_gacha_id")]
+    [Key("parent_gacha_id")]
+    public int ParentGachaId { get; set; }
+}

SVSim.UnitTests/Controllers/PackControllerLeaderSkinOwnedStatusTests.cs

@@ -0,0 +1,34 @@
+using System.Net;
+using System.Text;
+using System.Text.Json;
+using NUnit.Framework;
+using SVSim.UnitTests.Infrastructure;
+
+namespace SVSim.UnitTests.Controllers;
+
+public class PackControllerLeaderSkinOwnedStatusTests
+{
+    [Test]
+    public async Task GetLeaderSkinOwnedStatus_returns_nine_empty_buckets()
+    {
+        using var factory = new SVSimTestFactory();
+        long viewerId = await factory.SeedViewerAsync(tutorialState: 0);
+        using var client = factory.CreateAuthenticatedClient(viewerId);
+
+        var requestJson = """{"parent_gacha_id":99047,"viewer_id":"0","steam_id":0,"steam_session_ticket":""}""";
+        var response = await client.PostAsync("/pack/get_leader_skin_owned_status",
+            new StringContent(requestJson, Encoding.UTF8, "application/json"));
+
+        Assert.That(response.StatusCode, Is.EqualTo(HttpStatusCode.OK));
+
+        var body = await response.Content.ReadAsStringAsync();
+        using var doc = JsonDocument.Parse(body);
+        // Per spec: keys "0".."8" inclusive, each an empty object.
+        for (int classId = 0; classId <= 8; classId++)
+        {
+            var bucket = doc.RootElement.GetProperty(classId.ToString());
+            Assert.That(bucket.ValueKind, Is.EqualTo(JsonValueKind.Object));
+            Assert.That(bucket.EnumerateObject().Count(), Is.EqualTo(0));
+        }
+    }
+}