feat(design): one media card, and Home's hero and shelves as cards (E28 S3h)

- ui/MediaCard + mediaCardStyles: one frame for every video, Plex title and
  Home tile; the meta line pinned to the bottom edge, the length a badge on
  the picture, the media Play only where the click plays, the hover row at
  the picture's bottom-right (the owner's pick C).
- Shelf density: on any strip a one-line title over one meta line; mixed
  Home shelves are landscape; rails turn content-visibility off (a card's
  reserved height had become the strip's). Home slot 232px, so the Play
  and the hover row no longer touch; a landscape shelf takes the small Play.
- Home hero is a card (hover row, the whole menu, a touch "…"), three
  quarters wide and centred; channel / playlist tiles get Play, open and
  "…"; a show tile acts on its next episode, ⓘ opens the show.
- Plex preview: a ~0.9 s mouse rest opens a passive panel with the whole
  title, facts and synopsis (popover `pointerOnly`); the synopsis and title
  tooltips are gone.
- Compact list row B: the title leads, "…" at the end, toggles over the
  date on hover.
- Media-info layout B (collections, crew, cast beside the facts sidebar;
  an empty column is not drawn); filtering values are chips there and on
  the show page; "Cast" over the cast-only strips.
- Browse tiles hover like a card; prose capped by the `measure` utility.

frontend/src/components/ui/Carousel.tsx

@@ -132,7 +132,10 @@ export function Carousel({
             scroller clips its overflow, and the ring sits 4px outside the card it surrounds. */}
         <div
           ref={setScroller}
-          className={clsx("no-scrollbar -mx-1 -mt-1 flex overflow-x-auto px-1 pt-1 pb-1", gap)}
+          className={clsx(
+            "media-rail no-scrollbar -mx-1 -mt-1 flex overflow-x-auto px-1 pt-1 pb-1",
+            gap,
+          )}
           style={{ maskImage: mask, WebkitMaskImage: mask }}
           role="group"
           aria-label={label}