鉴定样例测试按钮（展示页用）

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

src/Decentralized/UsedDealerClient.cs

@@ -17,6 +17,7 @@ namespace Decentralized
         public static void Subscribe()
         {
             ModHook.OnGenerateCustomerNormal += OnGenerate;
+            ShowcaseCases.Register();
             ModHelper.AddAppraisalItem(ModInfo.Id, Appraisal, Items.GpuId("RTX60"), 2, CreateForAppraisal, u => (int)CardValue.True(Items.ToUnit(u)),
                 Items.IsGpu, Items.Guide, () => L.T("appraisal.gpu"));
             ModHelper.AddDebugFunction(ModInfo.Id, ModInfo.Name, "Appraisal client (test)", () => Log.Guard("鉴定客户（测试）", () =>
@@ -72,7 +73,7 @@ namespace Decentralized
             return item;
         }
 
-        private static StoreClient Create(DealerKind kind, int? atDay = null)
+        internal static StoreClient Create(DealerKind kind, int? atDay = null)
         {
             int day = atDay ?? StoreStation.GetDayCounter();
             var rng = Session.Data.Rng;