setup-gitignorelisted

Initialize or idempotently revise the current repo's `.gitignore` — never the global excludesfile. ## Scope Per-repo only. Never read or write `~/.gitignore`, `~/.config/git/ignore`, or run `git config --global`. The user's global excludesfile handles cross-machine noise; this skill handles language/tool specifics for the current repo. ## Sources composed (in order) 1. **gitignore.io** — templates keyed by detected language/framework (requires network) 2. **AI tooling** — bundled patterns from `references/AI-TOOLING.md` 3. **IDE / editor** — bundled patterns from `references/IDE-EDITOR.md` 4. **Empirical** — untracked paths from `git status`, confirmed interactively ## Workflow ### 1. Detect repo root ```sh git rev-parse --show-toplevel ``` Abort with a clear error if not inside a git repo. ### 2. Detect languages Read `references/LANGUAGE-DETECTION.md` for the manifest → gitignore.io key table. Scan manifests: ```sh fd --max-depth 2 -t f ``` Match filenames against the detection table; build a comma-separated key list (e.g., `rust,node,typescript`). If no manifests detected, use an empty key list (bundled blocks still apply). ### 3. Snapshot existing .gitignore If `.gitignore` exists, snapshot it before any modification: ```sh cp .gitignore /tmp/gitignore-snapshot-$(date +%s).bak ``` ### 4. Surface empirical noise ```sh git status -s -uall | rg '^\?\?' | rg -v '^\?\? \.gitignore' ``` Cluster untracked paths by top-level directory or extension. **Present clu