Order dispatch with debt accounting

Money operations are race-safe: a payout runs under a lock that re-checks the current debt, so a double click cannot pay twice, and reassigning an order marks the original through a compare-and-set. An access request is claimed atomically by exactly one manager.

Undelivered messages are handled by cause rather than as one generic error: when the text is too long there is no «Retry» button, because retrying will not help. When Telegram did not answer at all, the order stays active — the message may well have arrived.

Python · SQLite (WAL) · Telegram Bot API · http.server