Phase 2: mixer (Web3 tab in the network, terminal page, sanctions, night return), unlock registration per upgrade

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

src/Decentralized.Domain/Tuning.cs

@@ -57,6 +57,9 @@ 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>混币器：每轮手续费、基准清洗率、NPC 背景量（信用点）、最大轮数、最小存入、制裁概率与天数、每晚跑路概率。</summary>
+        public const double MixerFee = 0.02, MixerCleanRate = 0.35, MixerNpcVolume = 20000, MixerMin = 100, MixerSanctionChance = 0.5, MixerRugChance = 0.004;
+        public const int MixerMaxRounds = 5, MixerSanctionDays = 5;
         /// <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>