feat(upserver): 保存M2客户端KV迁移至本人统计写检查点

保存独立KV用户服务、固定会话存档与原业务接线，以及C3d资料缓存和C3e本人统计写。
保留原PF/AGG路线、业务公式和时序；榜单读取、好友资料、公告、匹配及首场景闸仍待完成。

验证：ServiceHost两条件各33组646断言；Unity CLI Loop编译0错误269警告。
包含相关方案、评审裁决、测试及状态文档。未操作服务器、正式账号或打包。

Client/Assets/Scripts/UI/Shop/BlackFridayCouponData.cs

@@ -1,10 +1,17 @@
-using System;
+using System;
 using System.Linq;
 using asap.core;
 using cfg;
 
 public class BlackFridayCouponData
 {
+    private game.PlayerDataStorage.IPlayerSaveStore saveStore;
+    internal void BindSaveStore(game.PlayerDataStorage.IPlayerSaveStore store)
+    {
+        if (saveStore != null && !ReferenceEquals(saveStore, store)) throw new System.InvalidOperationException("Archive store cannot change login.");
+        saveStore = store;
+    }
+
     private readonly Tables _tables = GContext.container.Resolve<Tables>();
     private readonly TbEventCoupon _tableCoupon = GContext.container.Resolve<Tables>().TbEventCoupon;
     public DateTime ActivateTime = new DateTime(1996, 11, 28);
@@ -70,7 +77,7 @@ public class BlackFridayCouponData
     {
         string s =
             $"{ActivateTime.Year},{ActivateTime.Month},{ActivateTime.Day},{ActivateTime.Hour},{ActivateTime.Minute},{ActivateTime.Second},{EventId},{RedirectId},{(IsBought ? 1 : 0)}";
-        PlayFabMgr.Instance.UpdateUserDataValue(PlayFabDataKey, s);
+        saveStore.Write(PlayFabDataKey, s).RequireAccepted();
     }
     public void UpdateData(FishingEvent e)
     {