Set up react-i18next with locale files auto-loaded per area (Vite glob), a compact
LanguageSwitcher, and language as a server-persisted preference (preferences.language)
mirrored to localStorage. On first login the default UI language is guessed from the
Google-reported locale (hu/en/de, else English). vite-env.d.ts types the build-time env.
Each filter group is now a card with a collapse chevron. An Edit mode (pencil)
reveals drag handles (@dnd-kit) to reorder and eye toggles to show/hide widgets,
plus Reset to defaults. Layout (order/collapsed/hidden) persists to localStorage
and the server preferences blob, adopted on login.
