Let's say a local file description page is protected, e.g. because of vandalism or an edit war. Users aren't able to edit such a local file any more, but they can move it to Commons, possibly continuing the vandalism/edit war on Commons.

Acceptance criteria:

• The FileExporter button should not be shown for users who can't edit the file and/or file description page on the source wiki.
• The FileImporter should not allow importing files if the current user can't edit the file and/or file description page on the source wiki.

Related: In the later situation, the source wiki editing feature (T225617) is expected to fail, but currently doesn't report this in a way the user can understand. Reported as T233576: Source wiki edit logic doesn't detect some failure cases.