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/KVGameLoadTests.csproj

@@ -5,6 +5,9 @@
     <RestoreConfigFile>$(MSBuildThisFileDirectory)../MinimalLoginTests/NuGet.Config</RestoreConfigFile>
   </PropertyGroup>
   <ItemGroup>
+    <Compile Include="../../../Client/Assets/Scripts/Core/KVMgr.cs" Link="Production/KVMgr.cs" />
+    <Compile Include="../../../Client/Assets/Scripts/Services/PlayerData/PlayerKVRuntimeSelection.cs" Link="Production/PlayerKVRuntimeSelection.cs" />
+    <Compile Include="../../../Client/Assets/Scripts/Services/PlayerData/PlayerKVKeyReadResult.cs" Link="Production/PlayerKVKeyReadResult.cs" />
     <Compile Remove="ServiceHost/**/*.cs" />
     <Compile Include="../../../Client/Assets/Scripts/Services/PlayerData/PlayerKVInitializationIntents.cs" Link="Production/PlayerKVInitializationIntents.cs" />
     <Compile Include="../../../Client/Assets/Scripts/Services/PlayerData/PlayerKVGameLoadTransaction.cs" Link="Production/PlayerKVGameLoadTransaction.cs" />