feat: 实现场景物体分层 + 桥碰撞 + 相机跟随修复 + 每周培育面板重做 - #23

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/