✨ Feat: 마이도도 로그아웃 및 회원 탈퇴 기능 구현 - #64

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-node@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

The 'notes' logical expression could make the dependencies of useMemo Hook (at line 54) change on every render. To fix this, wrap the initialization of 'notes' in its own useMemo() Hook