Redraw the monochrome icon and the header ambiences, and compare the installed manager - #849

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: seanmiddleditch/gha-setup-ninja@v6. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/