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)