Using Git Worktrees

Automatically picks the right directory (checks for existing .worktrees or worktrees folders, then CLAUDE.md preferences, then asks), verifies it won't get committed by accident, creates the worktree with a new branch, runs your project setup (npm install, cargo build, whatever), and confirms tests pass before you start. The ignore verification is critical because committing worktree contents is a mess to clean up. Required step before brainstorming moves to implementation or any subagent work starts, pairs with finishing-a-development-branch for cleanup.