## Summary
- New `mise run branch-cleanup` task that finds branches merged into main and deletes them locally and on the Forgejo remote
- Configurable `--cutoff` (default 30 days) skips branches with recent HEAD commits
- Supports `--dry-run`, `--local-only`, `--remote-only` flags
- Interactive confirmation before any deletion
## Test plan
- [x] `mise run branch-cleanup -- --dry-run` shows correct table of candidates
- [ ] Run without `--dry-run` to confirm actual deletion works
Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/247