fix(llm, openai): Stop a redeemed usage reset locking the account out - #1171

A turn that spends a reset credit now keeps trying for up to a minute
while the redemption reaches the responses host, instead of retrying
once and abandoning the turn. The account confirms a redemption before
the host honours it, so that single immediate retry almost always
landed in the gap: the credit was spent, the reset applied, and the
turn ended anyway with `Rate limited`.

Attempts go out every five seconds until the request is admitted. The
credit is spent by then and the turn is unfinished, so waiting is what
the user paid for; each attempt is an admission-stage rejection that
bills nothing. Exactly one credit is spent however long the wait runs.

The wait is bounded because the other explanation for the refusal — a
usage window the credit does not cover — looks identical from here and
never resolves. When the budget runs out the turn falls through to the
rest of the chain as before.

Signed-off-by: Jean Mertz <git@jeanmertz.com>