Phase 2: customers paying in coin (CRC/CRT/CRA/PSC), taint from stolen goods

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

src/Decentralized.Domain/CoinPayment.cs

@@ -0,0 +1,47 @@
+using System;
+
+namespace Decentralized.Domain
+{
+    /// <summary>
+    /// 顾客用币付款：成交的信用点在店里扣回，按当前币价换成币进热钱包。
+    /// 收赃物的款项不再记销赃，改为币带污点：货值 × 赃物热度%。
+    /// </summary>
+    public static class CoinPayment
+    {
+        /// <summary>各派系用什么币付款（其余派系不用币）。</summary>
+        public static string AssetFor(string faction)
+        {
+            switch (faction)
+            {
+                case "FACTION_UPPER_LEVEL": return Assets.CRC;
+                case "FACTION_BLACK_MARKET": return Assets.CRT;
+                case "FACTION_REVOLUTION": return Assets.CRA;
+                case "FACTION_LOWER_LEVEL": return Assets.PSC;
+                default: return null;
+            }
+        }
+
+        /// <summary>一位顾客用币付款的概率。</summary>
+        public static double Chance(string asset)
+        {
+            switch (asset)
+            {
+                case Assets.CRC: return Tuning.CoinPayCrc;
+                case Assets.CRT: return Tuning.CoinPayCrt;
+                case Assets.CRA: return Tuning.CoinPayCra;
+                default: return Tuning.CoinPayPsc;
+            }
+        }
+
+        /// <summary>收款：返回收到的币数。heatPct 是物品的赃物热度（0–100）。</summary>
+        public static double Receive(Wallet w, string asset, double credits, double price, double heatPct)
+        {
+            if (credits <= 0 || price <= 0) return 0;
+            double qty = credits / price;
+            w.Add(asset, qty);
+            w.Taint += credits * Math.Max(0, Math.Min(100, heatPct)) / 100.0;
+            w.Basis += credits;
+            return qty;
+        }
+    }
+}

src/Decentralized.Domain/Tuning.cs

@@ -57,6 +57,8 @@ namespace Decentralized.Domain
         public const int AmlWindowDays = 7;
         public const double AmlTaintRatio = 0.10, AmlHeavyRatio = 0.30, AmlMixerBonus = 0.30, AmlMaxChance = 0.9;
         public const double TaxRate = 0.08;
+        /// <summary>各派系顾客用币付款的概率。</summary>
+        public const double CoinPayCrc = 0.12, CoinPayCrt = 0.25, CoinPayCra = 0.25, CoinPayPsc = 0.10;
         /// <summary>单个金融违规事件记入的罪证上限。</summary>
         public const double CrimeEventCap = 400;