Fix: Replace Quick Buy/Details buttons with single Buy button using short IDs

- ProductCarouselService: Use Buy button with short IDs for products without images
- CallbackHandler: Fix HandleCategory to use Buy button with short IDs
- MenuBuilder: Remove obsolete SingleProductMenu method

This ensures consistent behavior across all product displays and fixes
the Details button that was broken due to GUID format incompatibility.

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

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

TeleBot/TeleBot/Handlers/CallbackHandler.cs

@@ -298,11 +298,23 @@ namespace TeleBot.Handlers
             {
                 foreach (var product in products.Items)
                 {
+                    // Create Buy button with short ID format
+                    var buyButton = new InlineKeyboardMarkup(new[]
+                    {
+                        new[]
+                        {
+                            InlineKeyboardButton.WithCallbackData(
+                                $"🛒 Buy {product.Name}",
+                                _mapper.BuildCallback("product", product.Id)
+                            )
+                        }
+                    });
+
                     await bot.SendTextMessageAsync(
                         message.Chat.Id,
                         MessageFormatter.FormatSingleProduct(product),
                         parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
-                        replyMarkup: MenuBuilder.SingleProductMenu(product.Id)
+                        replyMarkup: buyButton
                     );
                 }
                 

TeleBot/TeleBot/Services/ProductCarouselService.cs

@@ -91,12 +91,23 @@ namespace TeleBot.Services
                         }
                         else
                         {
-                            // If no image, send as text message instead
+                            // If no image, send as text message with Buy button
+                            var buyButton = new InlineKeyboardMarkup(new[]
+                            {
+                                new[]
+                                {
+                                    InlineKeyboardButton.WithCallbackData(
+                                        $"🛒 Buy {product.Name}",
+                                        _mapper.BuildCallback("product", product.Id)
+                                    )
+                                }
+                            });
+
                             await botClient.SendTextMessageAsync(
                                 chatId,
                                 FormatProductCaption(product),
                                 parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
-                                replyMarkup: MenuBuilder.SingleProductMenu(product.Id)
+                                replyMarkup: buyButton
                             );
                         }
 

TeleBot/TeleBot/UI/MenuBuilder.cs

@@ -542,16 +542,6 @@ namespace TeleBot.UI
             };
         }
 
-        public static InlineKeyboardMarkup SingleProductMenu(Guid productId)
-        {
-            return new InlineKeyboardMarkup(new[]
-            {
-                new[] {
-                    InlineKeyboardButton.WithCallbackData("🛒 Quick Buy", $"quickbuy:{productId}:1"),
-                    InlineKeyboardButton.WithCallbackData("📄 Details", $"product:{productId}")
-                }
-            });
-        }
 
         public static InlineKeyboardMarkup ProductMultiBuysMenu(Product product, int defaultQuantity = 1)
         {