feat: Fixed errors

LctMonolith/Services/Contracts/IStoreService.cs

@@ -0,0 +1,9 @@
+using LctMonolith.Models;
+
+namespace LctMonolith.Services.Contracts;
+
+public interface IStoreService
+{
+    Task<IEnumerable<StoreItem>> GetActiveItemsAsync(CancellationToken ct = default);
+    Task<UserInventoryItem> PurchaseAsync(Guid userId, Guid itemId, int quantity, CancellationToken ct = default);
+}