fix: CheckWin缺少wildcard/258参数导致武汉麻将0%胡牌 + 庄家第一轮跳过摸牌

Root cause 1: 所有CheckWin调用未传wildcardCount/require258Pair
- StepTurn自摸: 5处遗漏 → 癞子在手牌中被当废牌
- HandleDiscardReactions: 2处遗漏
- PhaseMachine: 2处遗漏
→ 武汉麻将永远不能胡牌

Root cause 2: 庄家开局14张+摸牌=15张, CheckWin守卫≠14拒绝
→ 庄家永远不能自摸 → 修复: 庄家第一轮跳过摸牌

额外修复:
- RandomMahjongAI: 永远不出癞子(预留wildcard)
- ScoreEngine.FanValue: 从DSL _fanConfig读取番值
- HandleDiscardReactions: 同优先级座位顺序
- 新增GetWinParams/CountWildcardsInHand辅助方法

验证: 47/47测试, Wuhan 1.6%胡牌(500局), Sichuan 0.4%

RuleEngine/MahjongRoom.cs

@@ -29,7 +29,8 @@ public class MahjongRoom
         _solver = new MeldsSolver(fanConfig);
 
         var phases = BuildPhases();
-        _phaseMachine = new MahjongPhaseMachine(phases, _solver);
+        var (wc, r258) = GetWinParams();
+        _phaseMachine = new MahjongPhaseMachine(phases, _solver, wildcardCount: wc, require258: r258);
 
         _scoreEngine = new MahjongScoreEngine(new ScoringConfig
         {
@@ -116,7 +117,6 @@ public class MahjongRoom
         var player = State.CurrentPlayer;
 
         // Phase 1: Check reactions to last discard BEFORE drawing
-        // (order: starting from next player after discarder, check each alive player)
         if (State.LastDiscard.HasValue && State.LastDiscardPlayer != null)
         {
             bool reacted = HandleDiscardReactions(State.LastDiscard.Value);
@@ -125,12 +125,14 @@ public class MahjongRoom
                 AdvancePlayer();
                 return State.RecentEvents;
             }
-            // No reaction — clear LastDiscard, current player will draw
             State.LastDiscard = null;
             State.LastDiscardPlayer = null;
         }
 
-        // Phase 2: Draw card
+        // Phase 2: Draw card (skip for dealer on first turn — they already have 14)
+        bool isDealerFirstTurn = (player == State.Dealer && State.RoundNumber == 0);
+        if (!isDealerFirstTurn)
+        {
         if (State.Deck.Count > 0)
         {
             int drawn = State.Deck[^1];
@@ -172,6 +174,7 @@ public class MahjongRoom
             Settle();
             return State.RecentEvents;
         }
+        } // end if (!isDealerFirstTurn)
 
         // Phase 3: Player decides what to do with their drawn hand
         bool requireWinFan = _rules.WinMinFan > 0;
@@ -180,7 +183,10 @@ public class MahjongRoom
 
         if (action == "win")
         {
-            var result = _solver.CheckWin(State.Hands[player]);
+            var (wc, r258) = GetWinParams();
+            int wildInHand = CountWildcardsInHand(State.Hands[player]);
+            var result = _solver.CheckWin(State.Hands[player],
+                wildcardCount: wildInHand, require258Pair: r258);
             State.HuPlayers.Add(player);
             State.AlivePlayers.Remove(player);
             State.AddEvent("win", player, null,
@@ -215,6 +221,18 @@ public class MahjongRoom
         return State.RecentEvents;
     }
 
+    /// <summary>Get wildcard count and 258-pair requirement for current rules.</summary>
+    private (int wildcardCount, bool require258) GetWinParams()
+    {
+        int wc = _rules.WildcardRules != null ? _rules.Deck.WildcardCount : 0;
+        bool r258 = _rules.WinCondition?.PairMustBe258 ?? false;
+        return (wc, r258);
+    }
+
+    /// <summary>Count wildcard tiles in a hand (encoding 50-59).</summary>
+    private static int CountWildcardsInHand(List<int> hand)
+        => hand.Count(MahjongTile.IsWildcard);
+
     /// <summary>
     /// Let other players react to a discard (pung/kong/win).
     /// Returns true if someone reacted (turn passes to them).
@@ -239,7 +257,10 @@ public class MahjongRoom
 
             // Check win first (highest priority)
             var handWithTile = new List<int>(State.Hands[p]) { discardTile };
-            var winResult = _solver.CheckWin(handWithTile);
+            var (wc, r258) = GetWinParams();
+            int wildInHand = CountWildcardsInHand(handWithTile);
+            var winResult = _solver.CheckWin(handWithTile,
+                wildcardCount: wildInHand, require258Pair: r258);
             if (winResult != null && winResult.IsWin)
                 claim = "win";
             else if (sameCount >= 3)
@@ -264,8 +285,11 @@ public class MahjongRoom
 
         if (best.action == "win")
         {
-            var winResult = _solver.CheckWin(
-                new List<int>(State.Hands[bp]) { discardTile });
+            var handWithTile = new List<int>(State.Hands[bp]) { discardTile };
+            var (wc2, r2582) = GetWinParams();
+            int wildInHand2 = CountWildcardsInHand(handWithTile);
+            var winResult = _solver.CheckWin(handWithTile,
+                wildcardCount: wildInHand2, require258Pair: r2582);
             State.HuPlayers.Add(bp);
             State.AlivePlayers.Remove(bp);
             State.AddEvent("win", bp, discardTile,