fix: 确定性牌计数推理 — UnknownCount修复 + 绝对大牌判断 + EndgameSolver修正

CardTracker:
- UnknownCount: 52→48 - handSize - seenCount (修正底牌+手牌漏算)
- 新增 RemainingCount/GetUnknownPool: 精确剩余牌计数
- 新增 IsAbsolutelyHighest: 全牌型确定性无敌判断 (单张/对子/三张/炸弹/顺子/连对/飞机)

EndgameSolver:
- GeneratePool → 调用 tracker.GetUnknownPool (修复已见牌未排除bug)

IsmctsBot:
- 确定性无敌出牌加成: 无敌出牌 +15-25% win rate bonus

SOIsmctsBot:
- 同步 UnknownCount(hand) 调用

验证: 100局0错误, 0.8s/局, ENDGAME求解正常触发

PdkFriendServer/Logic/IsmctsBot.cs

@@ -85,13 +85,13 @@ namespace PdkFriendServer.Logic
                         if (hand.Length == 0) return Pass(view);
 
                                     // 终局精确求解：手牌≤5 + 未知牌少 → 替代 ISMCTS
-                                    if (hand.Length <= 5 && _tracker.UnknownCount <= 15)
+                                    if (hand.Length <= 5 && _tracker.UnknownCount(hand) <= 15)
                                     {
                                         var endgameResult = EndgameSolver.Solve(hand, view, _tracker, _rng);
                                         if (endgameResult.HasValue)
                                         {
                                             var ep = endgameResult.Value;
-                                            Console.WriteLine($"[ISMCTS pos{view.MyPos}] ENDGAME hand={hand.Length} unknown={_tracker.UnknownCount} → 精确求解");
+                                            Console.WriteLine($"[ISMCTS pos{view.MyPos}] ENDGAME hand={hand.Length} unknown={_tracker.UnknownCount(hand)} → 精确求解");
                                             return new PlayOutCardPdkF
                                             {
                                                 Pos = (byte)view.MyPos,
@@ -255,6 +255,24 @@ namespace PdkFriendServer.Logic
                     }
                 }
 
+                // 5.6. 确定性无敌出牌：基于牌计数，如果某出牌绝对无人能压制 → 大幅加分
+                for (int i = 0; i < scoredCandidates.Count; i++)
+                {
+                    var (p, wr, am, m) = scoredCandidates[i];
+                    if (p.Type != CardType1.None && p.Ids != null && p.Ids.Length > 0)
+                    {
+                        if (_tracker.IsAbsolutelyHighest(hand, p.GameNum, p.Ids.Length, p.Type))
+                        {
+                            // 确定性无敌 → 大幅加分（相当于省掉 ISMCTS 模拟噪声）
+                            double bonus = 0.15;
+                            if (am <= 2) bonus = 0.25;    // 马上就要赢
+                            else if (m) bonus = 0.20;       // 多牌无敌
+                            wr += bonus;
+                            scoredCandidates[i] = (p, wr, am, m);
+                        }
+                    }
+                }
+
                 // 6. 两阶段选择：多牌优先
                 scoredCandidates.Sort((a, b) => b.winRate.CompareTo(a.winRate));
                 var best = scoredCandidates[0];