Limit active listings to 10

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

tests/Decentralized.Domain.Tests/Program.cs

@@ -695,6 +695,9 @@ internal static class Program
             bool rugged = false;
             for (int d = 2; d < 400 && !rugged; d++) { var ev = b4.Night(d, false, w4, new Rng((ulong)d * 31), 0, price); rugged = ev.Any(e => e.Kind == "sale_rug"); }
             Check(rugged && b4.Sales.All(x => x.State != SaleState.Listed && x.State != SaleState.Sold), "跑路：上架与未放款全部归零");
+            var b6 = new BlackMarket(); var w6 = new Wallet(); w6.Add(Assets.CRT, 100000);
+            int ok6 = 0; for (int i = 0; i < 15; i++) if (b6.List("c4", null, null, 0, 500, 1.0, w6, Assets.CRT, 1, price) != null) ok6++;
+            Check(ok6 == Tuning.BmMaxListings && b6.ActiveListings == 10, "同时最多上架 10 件");
             // 镇压期间不推进
             var b5 = new BlackMarket(); var w5 = new Wallet(); w5.Add(Assets.CRT, 1000);
             var s5 = b5.List("c4", null, null, 0, 500, 0.8, w5, Assets.CRT, 1, price);