When a video finishes and autoplay is on, instead of switching to the
next recommendation silently we show a YouTube-style end screen with
the next video's thumbnail, title and a radial countdown. The viewer
can Cancel to stay put, Play Now to skip the countdown, or just wait
and the existing _plOnVideoEnd / navigateNext handoff fires at zero.
End screen is skipped entirely when there's no sidebar card to show
or when loop is on (loop keeps the old same-video behavior).
Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>
