feat: 只加功能、不动架构（#53 返工版：多账号 / 四种登录方式 / 六渠道推送 / 日志页 / 深色模式） - #54

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