Clean up messy commit history into atomic commits before merge.
Use when user wants to restructure PR commit history based on final diff. Triggers include:
- Korean: "PR 히스토리 정리해줘", "커밋 히스토리 정리", "커밋 깔끔하게"
- English: "clean up commit history", "restructure commits", "organize commits"
- Context: User has messy commits (WIP, typo fixes) and wants atomic commit structure