The channel manager already styled the two deep-backfill-pending states
differently (solid clickable chip when you requested full history vs a faint
outline when another subscriber did), but both used the same "full history
queued" label, so a channel queued by someone else looked identical to one you
queued yourself. Give the by-other case its own label ("full history coming")
so the distinction is legible at a glance, not just on hover. Trilingual.
api: HttpError now carries the server's detail. Channels sync/backfill/unsubscribe
now detect a 403 (no YouTube grant) and show a 'connect your YouTube account'
message with a Connect action that opens the onboarding wizard, instead of a vague
'failed' toast. Translated HU/EN/DE.
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.
