Follows up on #432 (merged). Extracts _check_delegation_results_pending()
from the inline guard in _run_idle_loop() so tests can call the real
production function directly via patch(builtins.open, ...).
Fixes#401: the previous test used a mirror copy of the guard logic,
which risks drifting from the production implementation over time.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>