Foundation lib for v1.12.0 cron rewrite — closes brief deliverable
"log-rotate" that was missing from the original plan (Phase 9 scope
revision). Standard logrotate idiom, zero dependencies.
- rotateLog(logPath, opts) returns {rotated, dropped, kept}
- Defaults: maxSizeBytes 10 MB, maxGenerations 5 (1 active + 4 rotated)
- No-op when log missing or under threshold
- Over-size: drop oldest, shift .N..1 down by one, move active → .1
- maxGenerations=1 keeps only the active slot (no rotated copies)
- Pure stdlib fs.renameSync chain with silent try/catch on missing gens
8/8 tests pass: missing/under-size/over-size paths, chained 6 rotations
capped at maxGenerations, oldest dropped, two-step content shift.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Kjell Tore Guttormsen
aefe9ef5b4