cleanup-local-brancheslisted

# Cleanup Local Branches ## Purpose Prune dead local branches so the working copy only keeps branches that are still alive on origin or still recently active. Two deletion categories: - **Gone** — local branches whose upstream tracking branch was deleted on origin (e.g. the PR was merged and the origin branch removed). - **Stale** — local branches that have **no** counterpart on origin and have not received a commit for **more than six months**. --- ## Constraints - Apply `@rules/git/general.mdc` - Output must be in English - This skill deletes **local** refs only — it never deletes, force-pushes, or modifies any branch on origin - Never delete the currently checked-out branch - Never delete protected branches: `main`, `master`, `develop`, `development`, `production`, `staging`, or any branch matching `release/*` or `hotfix/*` - Always print the full deletion preview (branch, category, last commit date, integration status, planned action) **before** deleting anything - Never rewrite history, force-push, or run `git gc` / `git reflog expire` - Determine integration status by patch identity against the default branch (`git cherry`), so squash- and rebase-merged branches are recognized as integrated - Never delete a `stale` branch that is not integrated into the default branch automatically — keep it and report it unless the user explicitly authorizes force deletion (its commits never reached origin and are unrecoverable) --- ## Use when - The user asks to clean up, prune,