Installer asks for language first and translates supported console scripts

Merged

Sources

Ask for a language first and translate the installer into it
Translate the setup form from Omarchy's catalogs and let callers give a timezone fallback (#16049)
Let the setup form translate itself and take its defaults from the installer (#299)

dhh merged omarchybot's omacom/omarchy-iso#297 into quattro. The installer now starts with a language picker, provides translations for 35 languages alongside English and passes the selected language to the installed system. Keyboard defaults follow the language, with a capital-city timezone fallback where applicable.

Console font limits still matter: languages such as Japanese, Arabic and Vietnamese can be selected for the installed desktop, but their installation screens remain English. Subsequent quattro commits omacom/omarchy@4fa93e9f4c4f and omacom/omarchy-iso@31a65f89511a let the shared setup form read translations directly from Omarchy's catalogs, replacing the installer's English-text substitution wrapper.