fix(PX): 训练数据文件名加进程启动时间戳前缀，防止rsync覆盖旧文件

FlushGame 文件名从 game_00000.csv 改为 game_YYYYMMDD_HHMM_000000.csv。
_sessionPrefix 在类加载时固化，同一采集批次共享前缀，不同批次按启动时间区分。

PdkFriendServer/Logic/TrainingCollector.cs

@@ -14,6 +14,7 @@ namespace PdkFriendServer.Logic
     {
         public static bool Enabled = false;
         private static readonly List<TrainingRecord> _records = new List<TrainingRecord>();
+        private static readonly string _sessionPrefix = DateTime.Now.ToString("yyyyMMdd_HHmm");
 
         private static readonly int[] Ranks = { 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 16 };
         private const int NumRanks = 13;
@@ -43,7 +44,7 @@ namespace PdkFriendServer.Logic
         public static void FlushGame(int gameId, float[] rewards, int winnerPos, string[] botTypes)
         {
             if (!Enabled || _records.Count == 0) return;
-            var path = $"training_data/game_{gameId:D5}.csv";
+            var path = $"training_data/game_{_sessionPrefix}_{gameId:D6}.csv";
             System.IO.Directory.CreateDirectory("training_data");
             using var w = new System.IO.StreamWriter(path);
             w.WriteLine("state,action,q_value,player");