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/lib/plexPlayerHooks.ts

@@ -73,25 +73,50 @@ export function useFullscreen(wrapRef: RefObject<HTMLElement | null>): {
 // `holdOnHover` is the pointer resting on the chrome: the bar stays while it is there (as on YouTube
 // and Plex Web — E28 F22, it used to fade out from under a mouse parked on Next), and leaving it
 // starts a fresh 3 s.
+//
+// On touch (C3) nothing moves a mouse, so the timer is also armed by PLAYBACK starting — before, the
+// bar stayed up until the first tap however long the video played — and a tap on the picture only
+// shows or hides the bar (`toggle`), never pauses. `show(false)` hides at once: a double-tap skip
+// takes back the show/hide its first tap did.
 export function useControlsVisibility(opts: {
   barAutoHideRef: RefObject<boolean>;
   menuOpenRef: RefObject<boolean>;
   videoRef: RefObject<HTMLVideoElement | null>;
-}): { uiVisible: boolean; wake: () => void; holdOnHover: (over: boolean) => void } {
+}): {
+  uiVisible: boolean;
+  wake: () => void;
+  holdOnHover: (over: boolean) => void;
+  toggle: () => void;
+  show: (visible: boolean) => void;
+} {
   const { barAutoHideRef, menuOpenRef, videoRef } = opts;
   const [uiVisible, setUiVisible] = useState(true);
+  const visibleRef = useRef(true);
   const hideTimer = useRef<number | null>(null);
   const hovered = useRef(false);
+  const setVisible = useCallback((v: boolean) => {
+    visibleRef.current = v;
+    setUiVisible(v);
+  }, []);
   const wake = useCallback(() => {
-    setUiVisible(true);
+    setVisible(true);
     if (hideTimer.current) window.clearTimeout(hideTimer.current);
     if (!barAutoHideRef.current) return; // per-user setting: never auto-hide the control bar
     hideTimer.current = window.setTimeout(() => {
       // Keep the controls up while the audio/subtitle menu is open, else it would vanish mid-choice.
-      if (!videoRef.current?.paused && !menuOpenRef.current && !hovered.current)
-        setUiVisible(false);
+      if (!videoRef.current?.paused && !menuOpenRef.current && !hovered.current) setVisible(false);
     }, 3000);
-  }, [barAutoHideRef, menuOpenRef, videoRef]);
+  }, [barAutoHideRef, menuOpenRef, videoRef, setVisible]);
+  const show = useCallback(
+    (visible: boolean) => {
+      if (visible) return wake();
+      if (hideTimer.current) window.clearTimeout(hideTimer.current);
+      // A tap on a picture with a menu open closes nothing and must not strand that menu unseen.
+      if (!menuOpenRef.current) setVisible(false);
+    },
+    [wake, menuOpenRef, setVisible],
+  );
+  const toggle = useCallback(() => show(!visibleRef.current), [show]);
   const holdOnHover = useCallback(
     (over: boolean) => {
       hovered.current = over;
@@ -99,7 +124,19 @@ export function useControlsVisibility(opts: {
     },
     [wake],
   );
-  return { uiVisible, wake, holdOnHover };
+  useEffect(() => {
+    const video = videoRef.current;
+    if (!video) return;
+    video.addEventListener("play", wake);
+    return () => video.removeEventListener("play", wake);
+  }, [videoRef, wake]);
+  useEffect(
+    () => () => {
+      if (hideTimer.current) window.clearTimeout(hideTimer.current);
+    },
+    [],
+  );
+  return { uiVisible, wake, holdOnHover, toggle, show };
 }
 
 // Periodic + on-unmount progress checkpoint. Reads live position/duration through refs (owned by the