Under ar, Cities with Internet showed an Arabic legend over English country and
city names, while Prayer Progress localized its basemap. The helper already
exists in the library: localizeBasemapLabels (library/maps/localize-labels.js),
which is Mapbox setLanguage, and on MapLibre points each OSM-name label layer
at name:<lang>, then name:latin, then name. useMapInstance applies it for every
map built through it; connectivity-map builds its map raw (new gl.Map), so it
never ran here. It now runs on 'load' with the same reader-language ladder the
engine UI labels use. No library change: the helper was already shared.
Headless, the real helper against engine-shaped maps: under MapLibre ar, the 2
basemap label layers are rewritten and the plugin's own label (['get','iso3'])
is untouched; en restores the originals exactly. Under Mapbox ar-EG,
setLanguage('ar') is called. Build OK; no-free-identifiers, universal-props and
profiles-mount pass.
5643981601