Move SQL-dependent connection identity and /start bind work onto the
Gateway main loop via _submit_threadsafe_coroutine, and send PTB replies
through _run_on_telegram_loop so the Telegram worker never blocks or
touches SQLAlchemy/HTTP across event loops.
When the main loop is not running (e.g. during gateway shutdown), the
bind path logs a warning and returns False instead of running SQLAlchemy
on the wrong loop, matching the Feishu bind pattern.
74d9e6c2e0