Wikibase has many ResourceLoader modules that (as of 2023-01-06) don’t specify any targets, and thus are only available on desktop, not on mobile. However, it’s not always clear whether these modules are intentionally desktop-only, or whether they should also be enabled on mobile but were just missed so far. (Even if a module should be available on mobile, it’s of course possible that it requires some further code changes before it can actually work, of course.)

Per T326405, we don’t want to enable all the modules on mobile automatically, so we’re adding explicit 'targets' => [ 'desktop' ] to all modules that don’t specify targets yet (because the default targets are due to change soon); the purpose of this task is to then go through these modules and see how many of them we can change to 'targets' => [ 'desktop', 'mobile' ].