Git Worktree Discipline

Internal shared skill. Optional create/detect isolation before the first non-trivial write (docs or code). Hosts declare it in dependencies and abort if missing.

Name note: intentionally not named using-git-worktrees. Use git-worktree-discipline only. Operational create/detect/setup details live in reference.md (inspired by common worktree practice; no external skill dependency).

When to run

Before the first non-trivial persistent write (docs or code) in the host run. Skip the create offer only when already isolated for this change, or gate/never, or lean/hotfix in-place 留痕 this session.

Loop

1. Detect — already in a linked worktree for this change? Reuse (do not nest). Distinguish submodule from worktree before concluding isolation. Commands: reference.md.
2. Resolve preference — worktree-gate in AGENTS.md / CLAUDE.md: always | never | ask. Unset ≡ ask.
3. Recommend (ask / always) — suitability from project state (sibling ../ scripts, full product pack, dirty primary tree). Good for code + unit tests; poor for pack without path rebinding.
4. Act by gate
   • never → skip create; 【工作区隔离跳过】escape=worktree-gate-never；reason=…
   • always → create when possible (no ask)
   • ask → after recommendation, ask: create / decline / lean; do not silently create
5. Create — prefer the agent’s native workspace/worktree capability when available (avoids harness-invisible phantom git worktrees); else git fallback under ignored project-local dir (.worktrees/ preferred). Verify ignore with git check-ignore. Path priority and failure fallback: reference.md.
6. Setup + baseline — in the new workspace, run project-appropriate install/build and a baseline test/typecheck when the project has one; if baseline fails, report and ask whether to proceed or investigate. Skip install/baseline only when no project markers apply.
7. Lean/hotfix / decline — 【工作区隔离跳过】escape=lean-hotfix|user-decline；reason=…

Do not replace design approval. Do not silently destroy isolation mid-run. Do not imply one-click full product pack inside a worktree.

Cleanup ownership

Destroy/remove after verify/archive → feature-branch-closeout optional cleanup. This skill may note the remove command symmetric to create.

Integration guide

• Hosts: one line before the first artifact/code write — load this skill (worktree gate + optional isolation).
• Compose with feature-branch-closeout for cleanup only.
• Prefer user-invocable: false.
• Full detect/create/setup checklist: reference.md.