feature(find-child): export CUIWindow::FindChild to Lua and add UI casting exports - #653

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/upload-artifact@v4.6.0, al-cheb/configure-pagefile-action@v1.3, microsoft/setup-msbuild@v1.3.1, snickerbockers/submodules-init@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/