Reworks VideoInfoView on tvOS into a persistent 30% left sidebar
(thumbnail, title, channel, Play / Add to Playlist / Bookmark) with a
scrollable right pane for description, stats, comments, related, and
watch history. Reuses the player's TVScrollableDescription (refactored
to self-manage focus) so the description supports click-to-lock
scrolling, and the outer ScrollView is disabled while locked. Comments
full-screen on tvOS, with commenter avatars no longer tappable and
accent-colored link text replaced with the default foreground.
