Reorder the stop() method to cancel recv_task BEFORE closing the
connection. Previously, closing the connection first would set asyncio
transport callbacks to None while recv_worker() might still be reading,
causing 'TypeError: NoneType object is not callable' in
_SelectorSocketTransport._read_ready().

Update the supported Python range, development interpreter, dependencies, CI and contributor guidance. Apply Ruff pyupgrade migrations for the new minimum version.

Use asyncio.timeout for request writes and replies so cancellation propagates without leaving pending results on Python 3.11.

Add optional validated random_id parameters to single-message sending methods. Preserve automatic generation and document queue retries and Telegram deduplication limits.

Closes #70