Stage 6.3: RatDigg ASIC miners, miner dealers on the black market, miner era event

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

src/Decentralized.Domain/Mining.cs

@@ -152,6 +152,10 @@ namespace Decentralized.Domain
     public sealed class Network
     {
         public double NpcHash = Tuning.NpcHash0;
+        /// <summary>NPC 矿工每 H 的耗电（kJ）：矿机时代到来后减半，他们能挖得更久，全网算力均衡点升高。</summary>
+        public double NpcKj = Tuning.NpcKjPerH;
+        public int EraDay = -1, EraWarnDay = -1;
+        public bool EraWarned, EraDone;
         public double Reward = Tuning.BlockReward;
         /// <summary>停电、动荡等事件对 NPC 算力的可用比例。</summary>
         public double Availability = 1.0;
@@ -164,6 +168,25 @@ namespace Decentralized.Domain
             return Reward * playerHash / total * (1 - Tuning.PoolFee);
         }
 
+        public enum EraStep { None, Warn, Start }
+
+        /// <summary>
+        /// "矿机时代"：第一次调用时在 EraMin–EraMax 天之间随机定一天（至少留出预兆的天数），提前 4–7 天预兆，到点 NPC 耗电效率翻倍，永久。
+        /// 返回今晚发生的一步（预兆 / 开始）。
+        /// </summary>
+        public EraStep EraNight(int day, Rng rng)
+        {
+            if (EraDone) return EraStep.None;
+            if (EraDay < 0)
+            {
+                EraDay = Math.Max(day + Tuning.EraWarnMax + 1, rng.Range(Tuning.EraMin, Tuning.EraMax));
+                EraWarnDay = EraDay - rng.Range(Tuning.EraWarnMin, Tuning.EraWarnMax);
+            }
+            if (day >= EraDay) { NpcKj *= Tuning.EraKjMult; EraDone = true; return EraStep.Start; }
+            if (!EraWarned && day >= EraWarnDay) { EraWarned = true; return EraStep.Warn; }
+            return EraStep.None;
+        }
+
         /// <summary>
         /// 夜间：第 HalvingDays 天的倍数时减半；NPC 矿工按"每 H 收益 / 电费"与目标比的偏离扩张或关机，每晚最多 ±5%。
         /// </summary>
@@ -172,7 +195,7 @@ namespace Decentralized.Domain
             if (day > 0 && day % Tuning.HalvingDays == 0) Reward /= 2;
             double total = NpcHash * Availability + playerHash;
             double perH = Reward * price / total;
-            double ratio = perH / (Tuning.NpcKjPerH * Tuning.ElecPrice);
+            double ratio = perH / (NpcKj * Tuning.ElecPrice);
             double adj = Math.Max(-Tuning.NpcAdj, Math.Min(Tuning.NpcAdj, Tuning.NpcAdj * (ratio / Tuning.NpcTargetRatio - 1)));
             NpcHash *= 1 + adj;
         }