Flaky: test_a_rate_limited_body_fetch_keeps_retrying_on_retry_after_and_is_never_unavailable under the full suite #149

Seen once on the read-state-phase5c branch (#148), which does not touch claude_channel: uv run pytest --cov failed only tests/test_claude_channel.py::test_a_rate_limited_body_fetch_keeps_retrying_on_retry_after_and_is_never_unavailable (2484 passed). Run alone it passed 3/3, and an earlier full run of the same tree without --cov passed. The trace was not captured. Likely a timing dependence (retry-after or backoff against a real clock) that shows under load; worth checking the test for unfrozen time or a sleep.