Domain core: seeded RNG, asset registry, wallets, AMM pairs, mining

Pure logic layer with no game references: xoshiro128** RNG with savable
state, asset registry (PSC, CRC, CRT, CRA, SPARK, Ponero), wallets whose
taint and cost basis move with transfers, constant-product pools with
nightly reversion, and mining (Probidia/PMD GPUs, RatDigg ASICs, network
hash response, halving, wear and sudden death). 35 checks pass.

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

src/Decentralized.Domain/Wallet.cs

@@ -0,0 +1,54 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Decentralized.Domain
+{
+    /// <summary>
+    /// 一个链上地址：各币种余额，加上整个地址的污点额与成本（信用点等值）。
+    /// 污点和成本按转出的价值比例随币走。
+    /// </summary>
+    public sealed class Wallet
+    {
+        public string Address;
+        public Dictionary<string, double> Balances = new Dictionary<string, double>();
+        /// <summary>污点额（信用点等值）。</summary>
+        public double Taint;
+        /// <summary>成本（信用点）：出金时只对超出成本的部分征税。</summary>
+        public double Basis;
+        /// <summary>被执法标记。</summary>
+        public bool Flagged;
+
+        public double Get(string asset) => Balances.TryGetValue(asset, out var v) ? v : 0;
+
+        public void Add(string asset, double amount)
+        {
+            if (amount == 0) return;
+            double v = Get(asset) + amount;
+            if (v < -1e-9) throw new InvalidOperationException($"{Address}: {asset} 余额不足");
+            if (Math.Abs(v) < 1e-12) Balances.Remove(asset);
+            else Balances[asset] = v;
+        }
+
+        /// <summary>按价格表估值（信用点）。</summary>
+        public double Value(Func<string, double> price) => Balances.Sum(kv => kv.Value * price(kv.Key));
+
+        /// <summary>
+        /// 转出：taint 和 basis 按转出价值占地址总价值的比例带走。Ponero 等不可追踪资产转入时，污点不随之进入目标地址。
+        /// </summary>
+        public static void Transfer(Wallet from, Wallet to, string asset, double amount, Func<string, double> price)
+        {
+            if (amount <= 0) return;
+            double total = from.Value(price);
+            double share = total > 0 ? Math.Min(1.0, amount * price(asset) / total) : 0;
+            double taint = from.Taint * share, basis = from.Basis * share;
+            from.Add(asset, -amount);
+            from.Taint -= taint;
+            from.Basis -= basis;
+            to.Add(asset, amount);
+            var spec = Assets.Get(asset);
+            if (spec == null || spec.Traceable) to.Taint += taint;
+            to.Basis += basis;
+        }
+    }
+}