`_teach` signalled failure by negating the count taught so far. That
works for every case but the one that matters: when the FIRST message is
refused nothing has been taught yet, and `-0` is `0` — not negative. The
caller's `< 0` test then read a total engine outage as a clean run of
zero, recorded `_bootstrapped` for the account, and the hourly sweep
skipped it from then on. The account most in need of a warm start was
the one guaranteed never to get one.
Which is precisely what happened alongside the missing controller
password: every learn was refused 401, and each account was quietly
retired on its first sweep.
Return None for "the engine stopped accepting these" so failure cannot
be confused with a count, and decline to mark an account whose samples
were all unreadable.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018SqJYt7jD7oUEkoY68sBZo
lukasandClaude Opus 5
31edd4015e