Worktree isolation
establishedSettled. Documented by a primary source and not seriously disputed.
Giving each parallel agent its own checked-out directory over one shared object store. It works for what it claims — separate files, separate branches, no lock contention — and it is not a security boundary, which is the half nobody repeats. Object store, refs, config, stash and hooks all resolve to the shared common directory, so an agent inside a worktree can install a pre-commit hook that runs as you on your next commit. The usual objection to cloning instead — that it is slow — does not hold at the repository sizes anyone here works at. Worktree when a person drives; clone when something else does.