CleanMangaZip

Run all quality checks (test, lint, format verification)

Create a phased implementation plan in plans/ for cross-model review. Use before starting non-trivial features. The output file is designed to be reviewed by Codex CLI in Terminal 2 (Step 2 of the 4-step cycle). "plan", "計画を作って", "設計して" などで呼び出す。