Reusable platform module (lib/worktree.ts) that creates git worktrees
for test isolation and harvests useful changes as patches. Includes
SHA-256 dedup, original SHA tracking for committed change detection,
and automatic gitignored artifact copying (.agents/, browse/dist/).
12 unit tests covering lifecycle, harvest, dedup, and error handling.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Garry Tan