The "Subscribed on YouTube" inbox entry now names the channel and offers
two convenience links that survive a reload (driven by the typed payload,
not the live callback): "Channel manager" (jumps to the manager focused on
that channel) and "Open on YouTube". Wires the panel to the app's
focus-channel navigation; trilingual strings.
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.