Write credentials via a 0600 temp file + os.replace() so the token file
never appears at its final path with world-readable permissions, even if
the process is interrupted between write and chmod.
Parse poll_interval from the authorization response (clamped to 1–60 s,
falling back to _POLL_SLEEP) so aggressive polling can't trigger console
rate limits.
Tests: add atomicity spy asserting the temp file is 0600 before replace;
patch time.sleep instead of _POLL_SLEEP; add explicit interval-passthrough
assertion.
didericis-claude
2e1074b659