fix: Code Review — CheckTing完全断裂 + 座位顺序 + FanValue硬编码

🔴 Critical: CheckTing逻辑完全错误
- 旧: testHand.RemoveAt(i) → 13张 → CheckWin守卫拒绝(≠14) → 听牌检测永远false
- 新: 遍历所有可摸牌(27-34种), CheckWin(hand, newTile:tile) → 正确检测听牌
- 新增2个听牌测试

🟡 Medium: HandleDiscardReactions 同优先级顺序
- 旧: OrderByDescending取第一个，不保证座位顺序
- 新: 按座位顺序遍历，高优先级覆盖，同优先级先到先得

🟡 Medium: ScoreEngine.FanValue 硬编码番值
- 旧: switch expression 仅5种番型
- 新: 优先从 _fanConfig(DSL)读取，fallback到硬编码

🟢 Low: 删除硬编码的258将事件(非武汉也输出)

RuleEngine/Scoring/ScoreEngine.cs

@@ -13,11 +13,14 @@ public class MahjongScoreEngine
 {
     private readonly ScoringConfig _config;
     private readonly MeldsSolver _solver;
+    private readonly Dictionary<string, FanConfig> _fanConfig;
 
-    public MahjongScoreEngine(ScoringConfig config, MeldsSolver solver)
+    public MahjongScoreEngine(ScoringConfig config, MeldsSolver solver,
+        Dictionary<string, FanConfig> fanConfig)
     {
         _config = config;
         _solver = solver;
+        _fanConfig = fanConfig;
     }
 
     public void Settle(MahjongGameState state, string winner, MeldsResult result, bool isSelfDraw)
@@ -77,13 +80,19 @@ public class MahjongScoreEngine
         }
     }
 
-    private int FanValue(string fan) => fan switch
+    private int FanValue(string fan)
     {
-        "清一色" => 4,
-        "对对胡" => 2,
-        "暗七对" => 4,
-        "带幺九" => 2,
-        "十三幺" => 88,
-        _ => 1
-    };
+        if (_fanConfig.TryGetValue(fan, out var def))
+            return def.BaseFan;
+        // Fallback for fan names not in config
+        return fan switch
+        {
+            "清一色" => 4,
+            "对对胡" => 2,
+            "暗七对" => 4,
+            "带幺九" => 2,
+            "十三幺" => 88,
+            _ => 1
+        };
+    }
 }