2026-07-13 (itd-85 M1): kept `core.exists` (bool-only, swallows errors) and

2026-07-13 (itd-85 M1): kept core.exists (bool-only, swallows errors) and ahoy.fileExists (regular-file-only) as-is rather than folding all three exists copies into fsutil.Exists. Chose partial consolidation over the plan's full-consolidation because the other two hold different contracts; merging them would smuggle a behaviour change into a behaviour-preserving refactor. Only lint.fileExists (identical fail-closed contract) migrated.