The fixture used to DROP the shared llm_calls table on every run, wiping
concurrent migration-batch telemetry (and its own count assertion was
polluted in return). Assertions now filter by a per-run call_id prefix
and teardown deletes only its own rows.
Dual-channel opening: consecutive failures (CHS-compatible, no streak
bump) plus windowed failure rate (two 30s buckets, min_calls guard).
429s bypass both channels as backpressure, and a probe hitting 429
releases instead of holding the lease. Open duration doubles per
rate/probe reopen up to max_cooldown_s, decaying after stable CLOSED.
record_success gains count_attempt so bad-result successes stay out of
the window.
Classify empty completions as transient per human ruling (fixes flaky
real-gateway smoke and prevents caching empty responses), rename the
factory injection parameter gate to breaker per the frozen design,
rewrite the probe-entry cleanup without except BaseException, declare
python-dotenv explicitly, add a mid-backoff cancellation test, and
record all implementation errata in the design and architecture docs.
iomgaa