Add a shared resource-heading-tabs scroller with overflow chevrons,
wire it into resource/server navbars, keep links menus outside overflow,
and default new git apps to Railpack instead of Nixpacks.
- Reduced the size of SVG icons in the advanced application and service components from 6x6 to 4x4 for a more uniform appearance.
- Updated the external link component size in the services links to maintain visual consistency.
