feat(design): players on touch and the C5 control set, restart on the card (E28 S3f2)

Plex player: a finger's tap on the picture only shows or hides the controls,
the hide timer starts with playback, a double-tap on a side third skips 10 s,
the seek bar is a 2.75rem touch-none hit area with its head shown on touch.
The row is play/pause, Back by position, Next only with a next item, mute,
time, tracks, a fixed ⋯ (settings, media info, stats, shortcuts, download)
and fullscreen; Stop, Restart and the ±10 s buttons are gone.

A started card shows the video card's Continue + Restart pair (one shared
MediaResumeButtons, beside the picture's button), and its menu lists the
restart; the player opens that item at 0 (fromStart). YouTube modal: the
description opens from an ⓘ, the queue arrows sit inside the screen.

frontend/src/components/plexPlayerControls.tsx

@@ -4,49 +4,6 @@ import { RotateCcw } from "lucide-react";
 import { IconButton } from "./ui/IconButton";
 import { Slider as Range, Checkbox } from "./ui/NativeControls";
 
-// ±10s skip glyph: an outline circular arrow with a "10" in the centre — the YouTube/Plex-native
-// muscle-memory shape. Deliberately distinct from the episode-level SkipBack/SkipForward (double
-// triangles) and from Restart's plain RotateCcw. The arrowhead is an L-corner at the arc's open end,
-// the same construction lucide uses for RotateCcw/RotateCw, so it sits consistently in the bar.
-export function Skip10({ dir }: { dir: "back" | "forward" }) {
-  const back = dir === "back";
-  return (
-    <svg
-      viewBox="0 0 24 24"
-      fill="none"
-      stroke="currentColor"
-      strokeWidth={2}
-      strokeLinecap="round"
-      strokeLinejoin="round"
-      className="w-6 h-6"
-      aria-hidden="true"
-    >
-      {back ? (
-        <>
-          <path d="M4 8.5 A8 8 0 1 1 4 12" />
-          <path d="M4 8.5 L4 4 M4 8.5 L8.5 8.5" />
-        </>
-      ) : (
-        <>
-          <path d="M20 8.5 A8 8 0 1 0 20 12" />
-          <path d="M20 8.5 L20 4 M20 8.5 L15.5 8.5" />
-        </>
-      )}
-      <text
-        x="12"
-        y="14.5"
-        textAnchor="middle"
-        fontSize="8"
-        fontWeight={700}
-        fill="currentColor"
-        stroke="none"
-      >
-        10
-      </text>
-    </svg>
-  );
-}
-
 // --- settings-panel building blocks ------------------------------------------------------------
 export function PanelHead({ children }: { children: ReactNode }) {
   return (