feat: Implement payment notification system and API structure

- Added notifications for successful payments in `api/core/notifications.py`.
- Created main API entry point in `api/main.py` with FastAPI integration.
- Established routing structure in `api/routes/__init__.py` and `api/routes/pally.py` for handling payment callbacks.
- Developed billing handlers in `bot/handlers/billing.py` and `bot/handlers/buy.py` for subscription management.
- Introduced state management for user interactions in `bot/states/`.
- Created user interface elements in `bot/keyboards/` for navigation and payment processing.
- Set up middleware for dependency injection in `bot/middlewares/di.py`.
- Added support for user commands and interactions in `bot/handlers/common.py` and `bot/handlers/support.py`.
- Implemented logging and error handling throughout the bot's functionality.
- Created entry point script for API server in `entrypoints/api.sh`.

bot/main.py

@@ -0,0 +1,62 @@
+import asyncio
+import logging
+
+from aiogram import Bot, Dispatcher
+from aiogram.client.default import DefaultBotProperties
+from aiogram.client.session.aiohttp import AiohttpSession
+from remnawave import RemnawaveSDK
+
+from bot.handlers import routers
+from bot.middlewares import DIMiddleware
+from config import settings
+from db.session import async_session
+from misc.pally import PallyClient
+from repositories.bills import BillsRepository
+from repositories.users import UserRepository
+from schemas.di import DependenciesDTO
+from services.billing_service import BillingService
+from services.user_service import UserService
+
+logging.basicConfig(level=logging.DEBUG)
+
+
+async def main():
+    dp = Dispatcher()
+
+    pally_client = PallyClient(settings.pally_token)
+
+    user_repository = UserRepository()
+    user_service = UserService(user_repository)
+
+    bills_repository = BillsRepository()
+    billing_service = BillingService(
+        user_repository=user_repository, bills_repository=bills_repository
+    )
+
+    rw_sdk = RemnawaveSDK(
+        base_url=settings.remnawave_url,
+        token=settings.remnawave_token,
+    )
+
+    deps = DependenciesDTO(
+        user_repository=user_repository,
+        user_service=user_service,
+        rw_sdk=rw_sdk,
+        pally_client=pally_client,
+        bills_repository=bills_repository,
+        billing_service=billing_service,
+    )
+    dp.update.middleware.register(DIMiddleware(deps, async_session))
+
+    aiohttp_session = AiohttpSession(proxy=settings.proxy) if settings.proxy else None
+    default = DefaultBotProperties(parse_mode="HTML")
+    bot = Bot(token=settings.bot_token, default=default, session=aiohttp_session)
+
+    for router in routers:
+        dp.include_router(router)
+
+    await dp.start_polling(bot)
+
+
+if __name__ == "__main__":
+    asyncio.run(main())