The new `mul` language code functionality depends on pre-existing handling of languages (e.g. babels, fallback chain).
In mobile termbox, the languages listed are currently mostly hardcoded:
* Heading: English (for IPs), uselang (if logged-in, or set via uselang=)
* In more languages: English, German, French, Bavarian
* All entered languages: All entered languages
 We understand the status quo.
 We understand how hard will it be to implement handling of languages to the point we currently have on desktop (e.g. babels, fallback chain) (at least one possible option forward is described and roughly estimated, or if describing options forward is out of scope, explain what is needed to get to options forward).