Refactor configuration and enhance Telegram initData validation

- Improved formatting and readability in config.py and other files by adding line breaks.
- Introduced INIT_DATA_MAX_AGE_SECONDS to enforce replay protection for Telegram initData.
- Updated validate_init_data function to include max_age_seconds parameter for validation.
- Enhanced API to reject old initData based on the new max_age_seconds setting.
- Added tests for auth_date expiry and validation of initData in test_telegram_auth.py.
- Updated README with details on the new INIT_DATA_MAX_AGE_SECONDS configuration.

main.py

@@ -1,4 +1,5 @@
 """Single entry point: build Application, run HTTP server + polling. Migrations run in Docker entrypoint."""
+
 import asyncio
 import logging
 import threading
@@ -18,6 +19,7 @@ logger = logging.getLogger(__name__)
 def _run_uvicorn(web_app, port: int) -> None:
     """Run uvicorn in a dedicated thread with its own event loop."""
     import uvicorn
+
     loop = asyncio.new_event_loop()
     asyncio.set_event_loop(loop)
     server = uvicorn.Server(
@@ -31,6 +33,7 @@ def main() -> None:
     register_handlers(app)
 
     from api.app import app as web_app
+
     t = threading.Thread(
         target=_run_uvicorn,
         args=(web_app, config.HTTP_PORT),