Multi-Layer Stale State Debugging When a system shows persistent error signals despite reset conditions being met, check for stale state in three layers: (1) persistent config files with error timestamps, (2) cache files with synthetic entries, (3) code logic without staleness checks. Clear each layer independently, then add staleness detection (e.g., 12-hour threshold) to prevent recurrence. Verify fixes end-to-end before marking complete. ---