refactor: Home State를 4축으로 재설계 — 불법 조합을 표현 불가능하게 (Phase E5) - #374

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/