i18n: translate the catalog into Chinese, Japanese, Korean, Russian and Brazilian Portuguese

Add the 234 translatable strings in zh-Hans, ja, ko, ru and pt-BR,
bringing the app from 19 to 24 languages. Short/ambiguous strings were
translated off the human English pivot (e.g. Lire→Play, Plat→Flat) and
the 11 shouldTranslate:false keys were left untouched. pt-BR is kept
distinct from the existing European pt (Ajustes/Baixar/Salvar).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>