The TV quick-connect block (Подключить TV / Сканировать QR) is a Happ-only
feature (check.happ.su/sendtv), but it rendered for ANY app on a TV platform and
used one-off button styles (solid btn-primary + grey btn-secondary) that clashed
with the outlined-accent buttons that come from the subscription-page config.
- Show TvQuickConnect only for the Happ app (detected by its happ:// deep-link
scheme, name as fallback).
- Extract the config-block button style into a shared blockButtonClass and use it
for the TV buttons too, so they adapt to exactly the same visual language as the
panel-config blocks (no divergent one-off styling).
- Align the code input with the Happ Android TV API doc (5-digit numeric):
placeholder 12345 + inputMode numeric. The send call already matches the spec
(POST check.happ.su/sendtv/{code}, body {"data": base64(subscriptionUrl)}).
