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/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;