adds the /jellyfin screen and its two panels (nav + view) on top of the
jellyfin sidecar, following the photos/invoiceshelf shape.
the transcode path is a progressive mp4 rather than hls, so no hls.js
dependency is added under the frozen-install rule. that stream has no
length and no byte ranges, so the player owns its own scrubber and seeks
by re-negotiating at a new startTimeTicks, tracking offset + currentTime;
a direct file keeps native controls. the hls url is still returned, so
switching later is a player change only.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>