- Add validate_bot_token() to backend/telegram.py: calls getMe on startup,
logs ERROR if token is invalid (never raises per #1215 contract)
- Call validate_bot_token() in lifespan() after db.init_db() for early detection
- Update conftest.py make_app_client() to mock getMe endpoint
- Add 3 tests for validate_bot_token (200, 401, network error cases)
Root cause: CHAT_ID=5190015988 (positive) was wrong — fixed to -5190015988
on server per decision #1212. Group "Big Red Button" confirmed via getChat.
Service restarted.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
`async with await _get_conn()` запускал тред дважды: первый раз внутри
`_get_conn` через `await aiosqlite.connect()`, второй раз в `__aenter__`
через `await self`. Преобразован в `@asynccontextmanager` с `yield` и
`finally: conn.close()`. Все вызывающие места обновлены. Тест
`test_init_db_synchronous` обновлён под новый API.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
