Aside from MediaWiki:Common.js, MediaWiki already provides (local) MediaWiki:Group-sysop.js (.css) pages which will be loaded only for users in the associated groups, and MediaWiki:Vector.css (.js) which will load only in the specified skin.
Similarly, the extension could provide global JS/CSS for skins and user groups:
- MediaWiki:Global-group-sysop.js
- MediaWiki:Global-group-sysop.css
- MediaWiki:Global-vector.js
- MediaWiki:Global-vector.css
- ...
Version: unspecified
Severity: enhancement