Login page quietly probes /auth/demo (debounced) as a valid email is
typed/pasted and reloads into the app on a match — no visible button.
Demo sessions default to the whole library, get a one-time shared-account
warning, never see the YouTube-connect onboarding/access UI or sync
actions, and admins get a demo whitelist + reset panel in Settings.
Feed, VideoCard, Sidebar, PlayerModal, Channels, Stats, SettingsPanel,
OnboardingWizard, NotificationCenter, Toaster, ErrorBoundary and the relativeTime
helper are now fully translated in Hungarian, English and German, each with its own
locale area file (auto-loaded). Key parity verified across all three languages.
