Branch cleaner

Workflow

1. Resolve the repository, current branch, remote, and remote default branch from Git. Ask only when they remain ambiguous.
2. Fetch and prune remote-tracking refs, then collect evidence:
   • git status -sb
   • git worktree list --porcelain
   • git branch --merged <remote>/<default> and git branch --no-merged <remote>/<default>
   • git for-each-ref refs/heads --sort=committerdate --format="%(committerdate:iso8601) %(refname:short) %(upstream:short) %(upstream:track)"
3. When GitHub context is available, prefer the GitHub connector for open/merged PR metadata and branch protection context. Use gh only as a fallback.
4. Exclude the current branch, the default branch, branches checked out in any worktree, protected branches or rulesets, and branches with open PRs. If open-PR or protection state cannot be verified, keep the branch report-only.
5. Group candidates by evidence:
   • merged into the fetched default branch;
   • upstream gone;
   • old but unmerged, which is report-only unless the user explicitly approves force deletion.
6. Present concrete branch names, last commit dates, merge state, and local/remote scope before deleting anything.
7. Delete only approved candidates:
   • immediately before each deletion, fetch current evidence and recheck the branch tip SHA, worktree use, open PRs, and protection or ruleset state against the reviewed candidate;
   • skip the branch if its tip or state changed, or if any safety check is unavailable;
   • local merged branch: git branch -d <branch>;
   • remote branch: git push <remote> --delete <branch> only when remote deletion was explicitly requested;
   • use git branch -D only for an individually named unmerged branch explicitly approved by the user.
8. Re-run the candidate commands and git status -sb to verify the result.

Safety

• Treat age as a review signal, never proof that a branch is safe to delete.
• Never delete through an unresolved glob or a generated command string.
• Do not remove a branch used by another worktree.
• Do not delete remote branches or force-delete unmerged branches without explicit approval.
• Preserve unrelated working-tree changes.

Deliverable

Report deleted branches, skipped branches with reasons, commands run, and any candidates still needing a decision.