Fix: Delete order button now responds correctly

Root cause: Callback was answered twice (line 68 + HandleDeleteOrder)
- Telegram only allows answering callback query once
- Second attempt threw exception, preventing message edit
- Removed duplicate AnswerCallbackQueryAsync calls from HandleDeleteOrder
- Added proper error message for failed delete attempts
- Now shows success/failure via message edit instead of callback answer

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

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

TeleBot/TeleBot/Handlers/CallbackHandler.cs

@@ -1243,15 +1243,24 @@ namespace TeleBot.Handlers
                         }
                     })
                 );
-
-                await bot.AnswerCallbackQueryAsync(callbackQuery.Id, "Order deleted successfully");
             }
             else
             {
-                await bot.AnswerCallbackQueryAsync(
+                await bot.EditMessageTextAsync(
-                    callbackQuery.Id,
+                    callbackQuery.Message!.Chat.Id,
-                    "Failed to delete order. It may have already been processed.",
+                    callbackQuery.Message.MessageId,
-                    showAlert: true
+                    "❌ *Failed to Delete Order*\n\n" +
+                    "This order may have already been processed and cannot be cancelled.\n\n" +
+                    "Only orders in 'Pending Payment' status can be deleted.",
+                    parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
+                    replyMarkup: new InlineKeyboardMarkup(new[]
+                    {
+                        new[]
+                        {
+                            InlineKeyboardButton.WithCallbackData("⬅️ Back to Orders", "orders"),
+                            InlineKeyboardButton.WithCallbackData("🏠 Main Menu", "menu")
+                        }
+                    })
                 );
             }
         }