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。

CodexOutput/upserver/KVGameLoadTests/CoordinatorTests.cs

@@ -59,6 +59,19 @@ static partial class Tests
     }
     static async Task RunCoordinatorTests()
     {
+        await Run("M2-CP1-game-load-releases-guard-after-notification",()=>OnMain(async()=>
+        {
+            var f=new LoadFixture();
+            try
+            {
+                var result=await f.Coordinator.LoadForGameAsync("101",f.Capability());
+                Check(result.Error==PlayerKVGameLoadError.None && f.Notify==1,"complete apply and notification");
+                Check(!PlayerKVGameLoadGuard.Reject(PlayerKVGuardPoint.ReadLocal),"game success must release its load guard");
+                Check(result.State.ToString()=="GameLoaded" && !f.Coordinator.LoadedForValidation,"game success differs from validation");
+            }
+            finally { await f.Coordinator.Revoke(); }
+        }));
+        await RunGameHandoffTests();
         await Run("coordinator-success-reload-revoke-and-one-auth",()=>OnMain(async()=>
         {
             var f=new LoadFixture();