Feature: Complete order management for pending orders

- Added delete order functionality with identity verification
- OrderDetailsMenu now shows conditional buttons based on order/payment state
- Retry payment if no payments exist
- View payment details if payment pending
- Delete order option for all pending orders
- Full client SDK implementation for CancelOrderAsync

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

LittleShop.Client/Services/IOrderService.cs

@@ -11,4 +11,5 @@ public interface IOrderService
     Task<ApiResponse<Order>> GetOrderByCustomerIdAsync(Guid customerId, Guid orderId);
     Task<ApiResponse<CryptoPayment>> CreatePaymentAsync(Guid orderId, int currency);
     Task<ApiResponse<List<CryptoPayment>>> GetOrderPaymentsAsync(Guid orderId);
+    Task<ApiResponse<bool>> CancelOrderAsync(Guid orderId, string identityReference);
 }