Black market merchant shelves, bulk discount, bulk merchants, volume-driven taint, list-all

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

src/Decentralized.Domain/BmSales.cs

@@ -46,6 +46,13 @@ namespace Decentralized.Domain
         /// <summary>每晚成交的概率：1 / 期望天数，乘好评系数（好评 90 为 1，封顶 1.1），最多 1。</summary>
         public double SaleChance(double m) => Math.Min(1, 1 / ExpectedDays(m) * Math.Min(1.1, Rating / (double)Tuning.BmRatingStart));
 
+        /// <summary>近 7 天成交额推高的污点加成：出售量越大，货款越容易带污点、比例越高。</summary>
+        public double VolumeTaint(int day)
+        {
+            double v = Sales.Where(x => (x.State == SaleState.Sold || x.State == SaleState.Paid) && day - (x.PayDay - Tuning.BmSaleHold) <= 7).Sum(x => (double)x.Proceeds);
+            return Math.Min(Tuning.BmVolumeTaintMax, v / Tuning.BmVolumeRef * Tuning.BmVolumeTaintMax);
+        }
+
         public static int ListPriceOf(long refValue, double m) => (int)Math.Max(1, Math.Round(refValue * m));
         public static int ListFee(int listPrice) => (int)Math.Ceiling(listPrice * Tuning.BmListFee);
 
@@ -88,7 +95,8 @@ namespace Decentralized.Domain
                 }
                 s.State = SaleState.Sold;
                 s.Proceeds = (int)Math.Round(s.ListPrice * (1 - Tuning.BmCommission));
-                s.Taint = rng.Chance(TaintChance(s.Mult)) ? s.Proceeds * TaintRatio(s.Mult) : 0;
+                double vb = VolumeTaint(day);
+                s.Taint = rng.Chance(Math.Min(1, TaintChance(s.Mult) + vb)) ? s.Proceeds * Math.Min(1, TaintRatio(s.Mult) + vb) : 0;
                 s.PayDay = day + Tuning.BmSaleHold;
                 Rating = Math.Min(100, Rating + 1);
                 if (Honeypot(day)) Traps.Add(new BmTrap { Day = day + Tuning.BmTrapDelay, Amount = s.Proceeds, Why = "honeypot", Item = s.Item });