refactor: 생성되지 않던 TEST_RULES.md 연결, 프레임워크 규칙 중복과 미사용 코드 제거 - #4

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, actions/setup-python@v5. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/