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/B3BatchMigration/M2/M2-C3c第五轮状态核验hash.json

@@ -0,0 +1,30 @@
+{
+  "date": "2026-09-30T17:21:42.8188791+08:00",
+  "scope": "Fifth review status verification; reviewed subset not implemented, getter dependency conflict recorded",
+  "items": [
+    {
+      "path": "CodexOutput/upserver/B3BatchMigration/M2/M2-C3c第五轮状态核验与缓存联动边界-2026-09-30.md",
+      "bytes": 5315,
+      "sha256": "0130512B88C493FCC31A95E4B5C314779B82A2AA99B73EA59BFE84B9DBD0360B"
+    },
+    {
+      "path": "CodexOutput/upserver/B3BatchMigration/M2/M2-C3c剩余SDK接线独立差异审查-2026-09-30.md",
+      "bytes": 25343,
+      "sha256": "E0A9A124F98F36EED1CA902A14F6D890E5528A52D58B12C86183D2A26369560F"
+    },
+    {
+      "path": "Client/Assets/Scripts/Services/KVUserService.cs",
+      "bytes": 17714,
+      "sha256": "E7944DC489E726951D28C6B6C137C81A8099971EA6DC8EC304443C1628455CFA"
+    },
+    {
+      "path": "Client/Assets/Scripts/Services/UserService.cs",
+      "bytes": 37655,
+      "sha256": "11FF067AEC6AF420308D3CBFB000D5F88F877E9E589C413566F674DFD350D815"
+    }
+  ],
+  "profileCacheTestsExists": false,
+  "productionChanged": false,
+  "testsRun": false,
+  "formalRequests": 0
+}