Worktrees

Choose the feature workspace without disrupting one the user already chose. A named non-default branch stays in its current checkout; work that starts on main or master gets a feature branch and, when accepted, an isolated checkout. Separate checkouts make parallel /tracer-implement runs safe.

Order of preference: keep a named feature branch → reuse existing isolation → native harness tool → git worktree fallback. Never fight the harness.

0. Gate on the current branch

CURRENT_BRANCH=$(git symbolic-ref --quiet --short HEAD || true)

• If CURRENT_BRANCH is named and is neither main nor master, the repository already has a clear feature workspace. Stop this skill and work in the current checkout. A linked worktree is not required; the branch is the signal that the workspace has already been chosen.
• If CURRENT_BRANCH is empty, HEAD is detached or branch detection failed. Report the state and ask whether to keep working there or create a branch; do not create a worktree by assumption.
• Only when CURRENT_BRANCH is exactly main or master should this skill consider creating a worktree. Continue below.

1. Detect existing isolation