Stage 7.2: manipulation detection (player price push, prediction/perp forfeits)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/Decentralized.Domain/Market.cs

@@ -21,6 +21,15 @@ namespace Decentralized.Domain
         public List<Pool> Pools = new List<Pool>();
         /// <summary>开门时的参考价，夜间用它和收盘价算当日均价（合约的标记价）。</summary>
         public double OpenPrice = Tuning.PscStartPrice;
+        /// <summary>玩家自己的现货大单把价格推高（正）或压低（负）的对数幅度，每晚随价格回归一起衰减。操纵检出和预测盘用它估"没有玩家时的价格"。</summary>
+        public double PlayerPush;
+        public double NeutralPrice => Price * Math.Exp(-PlayerPush);
+        /// <summary>被查概率：推价幅度（绝对值）超过 ManipFree 后随幅度升高。</summary>
+        public static double ManipChance(double push)
+        {
+            push = Math.Abs(push);
+            return push < Tuning.ManipFree ? 0 : Math.Min(Tuning.ManipMax, Tuning.ManipBase + Tuning.ManipSlope * (push - Tuning.ManipFree));
+        }
 
         public const double ArbRate = Tuning.SideArbRate;          // 非主交易对每晚被拉回参考价的比例
         public const double SideDepthShare = Tuning.SideDepthShare;   // 非主交易对的深度占主交易对的比例
@@ -104,6 +113,7 @@ namespace Decentralized.Domain
         /// </summary>
         public void Night(ICollection<MarketEvent> active, Rng rng, int day, Func<string, double> stablePrice)
         {
+            PlayerPush *= 1 - Tuning.Revert;
             Sentiment *= Math.Exp(Tuning.SentimentKappa * -Math.Log(Sentiment) + rng.Gauss() * Tuning.SentimentVol);
             double anchor = Anchor(active);
             double lp = Math.Log(Price);