checkpointlisted

# Checkpoint Accept an optional slug-style name. Without a name, use a local-time `YYYY-MM-DD-HHmm` filename. A named checkpoint overwrites only the matching file when the user explicitly chose that name. 1. From the caller's original working directory, run `git rev-parse --show-toplevel`. Refuse outside a Git repository. Use `<repo-root>/docs/checkpoints/<name>.md`; never fall back to a shared home directory. Git's lookup handles linked worktrees. 2. Record what is visible in this conversation: a useful session summary, active goal and tasks if available, recent decisions, unresolved questions, and `git status --short` plus `git log --oneline -5`. Include statuses and dependencies for tasks when the current tools expose them. State unavailable information plainly; do not invent it. Omit secrets, tokens, and large output dumps. 3. Write a Markdown file with sections `Session summary`, `Active goal`, `Tasks`, `Decisions`, `Open questions`, and `Repo state`. Check the target path stays under this repository's `docs/checkpoints/`; create that directory if necessary. Do not stage or commit the file. 4. Report the absolute path written. Preserve the caller's other working-tree changes.