Refactor bot username retrieval in bulk promo code creation

- Updated the logic to retrieve the bot username dynamically, enhancing the accuracy of CSV links for promo codes.
- Improved error handling to log failures in fetching the bot username, ensuring better traceability.
- Adjusted the promo code service initialization in the start command handler to use the message context, improving consistency in bot interactions.

bot/handlers/admin/promo/bulk.py

@@ -439,8 +439,19 @@ async def create_bulk_promo_codes_final(callback_or_message,
                 "Команда для старта", "Ссылка для активации"
             ])
             
-            # Add bot username from settings
-            bot_username = getattr(settings, 'BOT_USERNAME', 'your_bot')
+            # Get real bot username
+            bot_username = 'your_bot'  # fallback
+            try:
+                if hasattr(callback_or_message, 'message'):
+                    bot = callback_or_message.message.bot
+                else:
+                    bot = callback_or_message.bot
+                
+                bot_info = await bot.get_me()
+                bot_username = bot_info.username or 'your_bot'
+            except Exception as e:
+                logging.error(f"Failed to get bot username for CSV links: {e}")
+                bot_username = 'your_bot'
             
             for code in created_codes:
                 # Determine validity info

bot/handlers/user/start.py

@@ -224,7 +224,7 @@ async def start_command_handler(message: types.Message,
     if promo_code_to_apply:
         try:
             from bot.services.promo_code_service import PromoCodeService
-            promo_code_service = PromoCodeService(settings, subscription_service, bot, i18n)
+            promo_code_service = PromoCodeService(settings, subscription_service, message.bot, i18n)
             
             success, result = await promo_code_service.apply_promo_code(
                 session, user_id, promo_code_to_apply, current_lang