Black-screen-on-play bug: rustypipe's default player() uses YT's Web
client, which serves stream URLs that are session/UA-locked. ExoPlayer
fetching with a different UA gets a silent 403 from googlevideo and
renders a black surface.
Fix: pin stream_info() to player_from_clients(id, [Tv, Ios]) — the
TVHTML5 + iOS Innertube clients serve direct-play URLs that work in
any HTTP player. Same trick NewPipe uses. No Apple/iOS code involved
— it's just the API client identifier rustypipe sends to YT.
Also added a Player.Listener in PlayerScreen that Toasts any
PlaybackException (codeName + message) so future stream failures don't
look like silent black screens. Logs to logcat 'StrawPlayer' too.