feat: NeuralBot — ONNX模型驱动的Bot + 混合Bot训练架构

NeuralBot.cs:
- 加载ONNX模型，状态编码与Python trainer完全一致(13rank×4suit×7ch=364)
- ε-greedy探索(10%) + ONNX推理选Q值最高动作
- 多牌候选: 对子/三带二(优先带对子)/顺子/炸弹

PdkGameMain:
- BotTypes静态配置: ["NEURAL","NEURAL","ISMCTS"] = 2模型+1ISMCTS
- --mix参数: dotnet run -- --mix 100

hjha-console:
- --mix参数自动设置BotTypes并转调--stress

验证: 3局0错误, 1.3s/局, NeuralBot出牌正常

PdkFriendServer/Logic/PdkGameMain.cs

@@ -56,12 +56,22 @@ namespace PdkFriendServer.Logic
             this.GamePack = new PdkGamePack();
         }
 
-        /// <summary>懒初始化3个bot（BotMode==true时首次WaitWanJiaShuRu调用）</summary>
-        private void InitBots()
+        /// <summary>懒初始化3个bot（BotMode==true时首次WaitWanJiaShuRu调用）
+                /// BotTypes: "ISMCTS" / "NEURAL" / null=默认ISMCTS
+                /// 训练模式: ["NEURAL","NEURAL","ISMCTS"] = 2个模型bot + 1个ISMCTS</summary>
+                public static string[] BotTypes = null;
+
+                private void InitBots()
                 {
                     _bots = new IPdkBot[3];
                     for (int i = 0; i < 3; i++)
-                        _bots[i] = new IsmctsBot();
+                    {
+                        string type = BotTypes != null && BotTypes.Length > i ? BotTypes[i] : null;
+                        if (type == "NEURAL")
+                            _bots[i] = new NeuralBot("model.onnx", 0.1f);
+                        else
+                            _bots[i] = new IsmctsBot();
+                    }
                 }
 
         /// <summary>构建当前玩家的可见视图——只看自己手牌+公开信息</summary>