feat(pack): gacha-point endpoint DTOs

SVSim.EmulatedEntrypoint/Models/Dtos/Responses/Pack/ExchangeGachaPointResponse.cs

@@ -0,0 +1,17 @@
+using System.Text.Json.Serialization;
+using MessagePack;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos.Responses.Pack;
+
+[MessagePackObject]
+public class ExchangeGachaPointResponse
+{
+    /// <summary>
+    /// POST-STATE TOTALS dispatched through PlayerStaticData.UpdateHaveUserGoodsNumByJsonData
+    /// on the client (see project_wire_reward_list_post_state memory). The granted card,
+    /// any cascading cosmetics, and the updated gacha-point balance entry all appear here.
+    /// </summary>
+    [JsonPropertyName("reward_list")]
+    [Key("reward_list")]
+    public List<RewardListEntry> RewardList { get; set; } = new();
+}