Ponero fee 6%/cap 1000, mixer fee 3%, brand-new GPUs on the black market

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

tests/Decentralized.Domain.Tests/Program.cs

@@ -702,6 +702,23 @@ internal static class Program
             Check(s5.State == SaleState.Listed, "镇压期间平台下线，不成交");
         });
 
+        Test("黑市全新卡", () =>
+        {
+            int fresh = 0, total = 0, bad = 0;
+            for (int i = 0; i < 300; i++)
+            {
+                var bm = new BlackMarket();
+                bm.Refresh(10, 75, new Rng((ulong)i + 11), id => 100);
+                foreach (var o in bm.Offers.Where(x => x.Kind == GoodKind.Gpu))
+                {
+                    total++;
+                    if (o.Health >= 100) { fresh++; if (o.FakeOf != null) bad++; }
+                }
+            }
+            Check(total > 300 && fresh > total * 0.08 && fresh < total * 0.25 && bad == 0, $"显卡里约 {Tuning.BmGpuNew:P0} 是全新卡，且不会是假卡：{fresh}/{total}，假 {bad}");
+            Check(Near(Tuning.PoneroFee, 0.06, 1e-9) && Near(1 - Math.Pow(1 - Tuning.PoneroFee, 2), 0.12, 0.01), "Ponero 一进一出约 12%");
+        });
+
         Console.WriteLine($"\n{_passed} 通过，{_failed} 失败");
         return _failed == 0 ? 0 : 1;
     }