Worktree Isolation Ensure the current work happens in an isolated workspace, without disturbing the user's main checkout. Most coding harnesses now create a worktree by default at session start, so the common case is that isolation already exists . Done when: the caller is working in an isolated tree — existing or newly created — and its path and branch have been reported, or a blocker has been reported instead. Order of operations: detect existing isolation - prefer a native worktree tool - fall back to plain git. Never create a worktree the harness cannot see. Two modes, set by the caller's…