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/Services/PlayerData/PlayerKVControlledLoadCapability.cs

@@ -17,6 +17,7 @@ namespace game.PlayerDataStorage
         internal string CacheRoot { get; }
         internal int LoginObserveMs { get; }
         internal int QuitObserveMs { get; }
+        internal bool RequireExistingArchive { get; }
         internal Func<int,CancellationToken,Task> Delay { get; }
         internal PlayerKVControlledLoadCapability LeaseCapability { get; private set; }
         readonly PlayerKVControlledLoadCapability auth,kv,lease;
@@ -28,7 +29,8 @@ namespace game.PlayerDataStorage
         bool claimed;
         private PlayerKVGameLoadCapability(PlayerKVIdentitySnapshot identity,PlayerKVSchemaSnapshot snapshot,Uri api,string cacheRoot,
             int loginMs,int quitMs,Func<int,CancellationToken,Task> delay,
-            PlayerKVControlledLoadCapability auth,PlayerKVControlledLoadCapability kv,PlayerKVControlledLoadCapability lease)
+            PlayerKVControlledLoadCapability auth,PlayerKVControlledLoadCapability kv,PlayerKVControlledLoadCapability lease,
+            bool requireExistingArchive=false)
         {
             Identity=identity ?? throw new ArgumentNullException(nameof(identity)); Snapshot=snapshot ?? throw new ArgumentNullException(nameof(snapshot));
             if(api==null || !api.IsAbsoluteUri || (api.Scheme!="http" && api.Scheme!="https") || !string.IsNullOrEmpty(api.UserInfo) ||
@@ -36,6 +38,19 @@ namespace game.PlayerDataStorage
                 loginMs<1000 || loginMs>15000 || quitMs<1000 || quitMs>15000) throw new ArgumentException("Controlled load configuration invalid.");
             Api=new Uri(api.AbsoluteUri.TrimEnd('/')+"/"); CacheRoot=cacheRoot;
             LoginObserveMs=loginMs; QuitObserveMs=quitMs; Delay=delay ?? Task.Delay; this.auth=auth; this.kv=kv; this.lease=lease;
+            RequireExistingArchive=requireExistingArchive;
+        }
+        internal static PlayerKVGameLoadCapability CreateForGame(PlayerKVIdentitySnapshot identity,PlayerKVSchemaSnapshot snapshot,
+            Uri api,string cacheRoot,Func<CookieContainer,HttpMessageHandler> auth,Func<CookieContainer,HttpMessageHandler> kv,
+            Func<CookieContainer,HttpMessageHandler> lease)
+        {
+            if(api==null || api.AbsoluteUri!="http://s101.local:18080/")
+                throw new ArgumentException("Formal KV endpoint mismatch.",nameof(api));
+            var capability=new PlayerKVGameLoadCapability(identity,snapshot,api,cacheRoot,10000,5000,null,
+                PlayerKVControlledLoadCapability.CreateForGame(auth),PlayerKVControlledLoadCapability.CreateForGame(kv),
+                PlayerKVControlledLoadCapability.CreateForGame(lease),true);
+            capability.LeaseCapability=PlayerKVControlledLoadCapability.CreateForGame(capability.TakeLease);
+            return capability;
         }
 #if UNITY_EDITOR
         internal static PlayerKVGameLoadCapability CreateForValidation(PlayerKVIdentitySnapshot identity,PlayerKVSchemaSnapshot snapshot,
@@ -65,7 +80,7 @@ namespace game.PlayerDataStorage
                 {
                     // Validate all three returned handler graphs before the first authentication send.
                     authentication=auth.CreateHandler(jar); pendingKV=kv.CreateHandler(jar); pendingLease=lease.CreateHandler(jar);
-                    if(ReferenceEquals(authentication,pendingKV) || ReferenceEquals(authentication,pendingLease) || ReferenceEquals(pendingKV,pendingLease))
+                    if(ShareHandlerGraph(authentication,pendingKV,pendingLease))
                         throw new InvalidOperationException("Distinct transport ownership required.");
                     return authentication;
                 }
@@ -77,6 +92,17 @@ namespace game.PlayerDataStorage
                 }
             }
         }
+        static bool ShareHandlerGraph(params HttpMessageHandler[] roots)
+        {
+            var seen=new System.Collections.Generic.List<HttpMessageHandler>();
+            foreach(var root in roots)
+                for(var node=root;node!=null;node=(node as DelegatingHandler)?.InnerHandler)
+                {
+                    if(seen.Exists(previous=>ReferenceEquals(previous,node))) return true;
+                    seen.Add(node);
+                }
+            return false;
+        }
         HttpMessageHandler TakeKV(CookieContainer jar)
         {
             lock(gate)