This page is just a note to explain what I've done. I think you'll find the Maintenance link more useful. But if these modifications to the Sidebar prove to be problematic, an administrator can delete the page MediaWiki:Common.js and (once MediaWiki has refreshed its caches) the site will revert to the old behavior.
I've leave this page here for a while, but eventually I propose to delete it and also remove the link to Special:SpecialPages from the Sidebar.
If these modifications to the Sidebar work out, though, then the same infrastructure can be used to add/change/remove other links from the Toolbox section of the Sidebar. (The upper sections of the Sidebar are easy to modify, just edit the page MediaWiki:Sidebar.)