stream_info(url) UniFFI suspend fn replaces NewPipeExtractor's
StreamInfo.getInfo() for both VideoDetailViewModel and PlayerViewModel.
One Rust round-trip drives the detail screen render AND the player's
resolve(). The VideoDetailUiState.info field cached on detail load is
reused by the Download dialog so we don't refetch.
Deferred to U-3.5:
- like_count (rustypipe's player() doesn't surface engagement data;
a separate query is needed)
- related (player() doesn't include 'up next'; comes from a separate
endpoint). Kotlin gets empty list for now — RelatedRow handles it.
Type quirks vs my initial guesses (caught by cargo check):
- details.duration is u32, not Option<u32>
- channel is split into channel_id + channel_name, not a struct
- like_count doesn't exist at this query depth
- VideoFormat::Webm (lowercase mb), VideoCodec::Avc1 (not H264)
- video_only is a separate vec (video_only_streams), not a bool flag
