workspace-isolationlisted

# Workspace Isolation Use this before substantial implementation starts. The goal is to protect the user's current checkout and create baseline evidence without fighting the runtime. ## Ownership - Top-level session or PM/coordinator owns isolation decisions. - Specialists may request this skill through `NEEDS_CONTEXT` when the packet lacks workspace, branch, or baseline facts. - Do not create, remove, or rewrite worktrees as a delegated specialist unless PM explicitly assigned that setup task. ## Flow 1. Detect current state: - `git rev-parse --show-toplevel` - `git rev-parse --git-dir` - `git rev-parse --git-common-dir` - `git rev-parse --show-superproject-working-tree` - `git branch --show-current` - `git status --short` 2. If `git-dir` and `git-common-dir` differ and the repo is not a submodule, treat the checkout as already isolated. Record path, branch or detached state, and skip worktree creation. 3. Prefer runtime-native workspace/worktree tools when available. Do not use manual `git worktree` when the host runtime owns isolation. 4. Manual worktree fallback is allowed only when the user already authorized implementation or isolation and the target directory is safe: - Prefer an existing ignored `.worktrees/` directory. - Otherwise prefer an existing ignored `worktrees/` directory. - If no ignored project-local directory exists, return `NEEDS_USER_INPUT` with options: add an ignored `.worktrees/`, use a user-named location, or work in p