Workspace Isolation Discipline

Internal shared skill. Optional create/detect isolation before production implementation. Hosts declare it in dependencies and abort if missing.

Name note: intentionally not named using-git-worktrees. Use this name only.

When to offer

After design-approval-gate passes (or auto escape), before non-trivial production edits. Skip offer only when: already isolated for this change, or lean/hotfix in-place 留痕, or user preference already recorded this session.

Loop

1. Detect — existing worktree / isolated path for this branch or change?
2. Offer — create isolation (prefer agent/platform native workspace tools if available; else git worktree add under .worktrees/<branch-slug>/). Ensure .worktrees/ is gitignored when creating.
3. Consent — user declines → continue in current worktree; record decline briefly.
4. Lean/hotfix escape — 【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.