Prediction markets: news reaction, clues, gas/CRA/era markets, intel broker, bigger stakes

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

src/Decentralized.Domain/Wallet.cs

@@ -108,6 +108,14 @@ namespace Decentralized.Domain
         }
 
         /// <summary>按价格表估值（信用点）。</summary>
+        /// <summary>花掉（销毁）一笔币：污点与成本按这笔币占钱包总价值的比例一起带走。</summary>
+        public void Spend(string asset, double amount, Func<string, double> price)
+        {
+            double total = Value(price), share = total > 0 ? Math.Min(1, amount * price(asset) / total) : 0;
+            double taint = Taint * share, basis = Basis * share;
+            Add(asset, -amount); Taint -= taint; Basis -= basis;
+        }
+
         public double Value(Func<string, double> price) => Balances.Sum(kv => kv.Value * price(kv.Key));
 
         /// <summary>