Cards: 3x2 front/back sprites, appearance overlays, flip via the Toggle menu

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

src/Decentralized/DealerStock.cs

@@ -15,6 +15,14 @@ namespace Decentralized
             ModHook.OnPlaceInventorInventoryItemLate += OnPlace;
             // 开发者模式（F9）里的测试入口：像到了杰克逊店里一样，清空并扩大柜台后上货
             ModHelper.AddDebugFunction(ModInfo.Id, ModInfo.Name, "Give rig x3 (test)", () => { for (int i = 0; i < 3; i++) Items.Give(ModHelper.SpawnItem(Items.Rig)); });
+            ModHelper.AddDebugFunction(ModInfo.Id, ModInfo.Name, "Used cards x4 (test)", () =>
+            {
+                var rng = Session.Data.Rng;
+                Items.Give(Items.NewCard("RZX80Ti", 40, null, rng));
+                Items.Give(Items.NewCard("RZX80Ti", 70, "RZX60", rng));
+                Items.Give(Items.NewCard("RZ6800", 30, "RZ580", rng));
+                Items.Give(Items.NewCard("RZ7900", 90, "RZ470", rng));
+            });
             ModHelper.AddDebugFunction(ModInfo.Id, ModInfo.Name, "Dr. Jackson stock (test)", () =>
             {
                 EmporiumEntry.Instance.ClearFrontInv();