Split cheatsheet into separate RU/EN <dd> elements with CSS class
toggle. Toggle buttons in nav bar (RU/EN). Language also controlled
by ?lang=ru|en query parameter (default: ru).
The rest of the PWA stays English; voice responses remain Russian.
Temporary reference while testing utterances: a collapsible <details> panel
(native, no JS) listing the six router intents (act/reminder/fact/note/query/
system) with real example phrasings pulled from models/seeds, RU-first since
the voice lang is ru.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>