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-好友KV资料接口设计受审hash.json

@@ -0,0 +1,41 @@
+{
+  "date": "2026-09-30T16:59:52.5902678+08:00",
+  "scope": "User-authorized friend KV public-profile API design for server implementation; proposal, not deployed or approved for coding",
+  "count": 6,
+  "items": [
+    {
+      "path": "CodexOutput/upserver/B3BatchMigration/M2/M2-好友KV资料服务端接口设计-待完整审核-2026-09-30.md",
+      "bytes": 10707,
+      "sha256": "30B5A5C5EEDF7D850DCB2DC01EC773036B9CC0F880D9818BFF5357DF90EAB093"
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+      "bytes": 2432,
+      "sha256": "D3FE30FDCBE18B787C4168FCADE644629010DE908BC5C362EDBFF5E0ECE860C0"
+    },
+    {
+      "path": "Client/Assets/Scripts/Services/FriendService.cs",
+      "bytes": 16510,
+      "sha256": "749ABCF06DD93B94211281479532392FD11D83CA5E413B6648EB04EBB24DD451"
+    },
+    {
+      "path": "Client/Assets/Scripts/Services/FriendModel.cs",
+      "bytes": 6227,
+      "sha256": "BEE90A493DBE3210AACD3D4062EEBDE1110A07D6E130ECCD67D5423A99091E39"
+    },
+    {
+      "path": "Client/Assets/Scripts/Services/KVUserService.cs",
+      "bytes": 17714,
+      "sha256": "E7944DC489E726951D28C6B6C137C81A8099971EA6DC8EC304443C1628455CFA"
+    },
+    {
+      "path": "Client/Assets/Scripts/Stages/FishingStage.cs",
+      "bytes": 26235,
+      "sha256": "EAD146F3BC9D3B5A7C73E8758A51934FACDA776DFB3D4A61443CB0E4E4E4884B"
+    }
+  ],
+  "jsonExamplesValidated": 2,
+  "productionChanged": false,
+  "serverChanged": false,
+  "formalRequests": 0
+}