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/Assets.cs

@@ -0,0 +1,51 @@
+using System.Collections.Generic;
+
+namespace Decentralized.Domain
+{
+    /// <summary>资产的性质。新增币种只是往 <see cref="Assets"/> 里加一条。</summary>
+    public sealed class AssetSpec
+    {
+        public string Id;
+        /// <summary>挂钩 1 信用点的稳定币。</summary>
+        public bool Stable;
+        /// <summary>发行方可以冻结地址（CRC；CRT 只在镇压期间）。</summary>
+        public bool Freezable;
+        /// <summary>链上可追踪：污点随币传播。Ponero 为 false，换入时污点停止传播。</summary>
+        public bool Traceable = true;
+        /// <summary>合规交易所可以上架。</summary>
+        public bool Compliant = true;
+        /// <summary>程序生成或玩家发行的代币。</summary>
+        public bool Issued;
+    }
+
+    /// <summary>资产登记。信用点（游戏现金）不在链上，不登记。</summary>
+    public static class Assets
+    {
+        public const string PSC = "PSC";
+        public const string CRC = "CRC";
+        public const string CRT = "CRT";
+        public const string CRA = "CRA";
+        public const string SPARK = "SPARK";
+        public const string Ponero = "PONERO";
+
+        private static readonly Dictionary<string, AssetSpec> Table = new Dictionary<string, AssetSpec>();
+
+        static Assets()
+        {
+            Register(new AssetSpec { Id = PSC });
+            Register(new AssetSpec { Id = CRC, Stable = true, Freezable = true });
+            Register(new AssetSpec { Id = CRT, Stable = true, Freezable = true });
+            Register(new AssetSpec { Id = CRA, Stable = true });
+            Register(new AssetSpec { Id = SPARK });
+            Register(new AssetSpec { Id = Ponero, Traceable = false, Compliant = false });
+        }
+
+        public static void Register(AssetSpec spec) => Table[spec.Id] = spec;
+
+        public static bool TryGet(string id, out AssetSpec spec) => Table.TryGetValue(id, out spec);
+
+        public static AssetSpec Get(string id) => Table.TryGetValue(id, out var s) ? s : null;
+
+        public static IEnumerable<AssetSpec> All => Table.Values;
+    }
+}