feat(e24): pin to the comfort shelf from every card and row

S3 wires the shelf's editor. The gesture is the E10 right-click menu, so the
decision "this is comfort media" can be made where the thing is — the feed, a
Plex grid, a channel row, a playlist — rather than only on the page that lists
the shelf.

One shared piece, `components/comfortPin.tsx`: the five pin-kind constructors,
the shelf query, and ONE `ActionMenuItem` that switches Pin/Unpin honestly (and
says "not known yet" with a disabled row until the shelf has answered, since a
confident "Pin" over something already pinned is exactly the quiet lie the house
rules forbid). Surfaces that already have a row menu compose the item in
(`Playlists`, `PlaylistsRail`); the rest mount `ComfortPinMenu`.

Two structural notes:

- The feed's menu lives in `VirtualFeed`, not in `Feed` — that is the list, and
  it is also what gives the channel page the gesture for free, since it renders
  `<Feed channelScoped>` all the way down.
- Cards take `menuProps` as a FUNCTION of the row, not the built props object.
  `triggerProps` is stable across renders while its return value is not, and a
  fresh object prop would blow past `VideoCard`'s memo for every card in the
  virtualized feed on every parent render.

`DataTable` and `ChannelLayoutGrid` grow a generic `rowProps` so a channel row
answers the same gesture in both of the manager's layouts; the table stays
domain-free and never learns what a menu is.

On Home the shelf tile's menu is the whole editor: four move rows (front / left
/ right / end, reusing the playlist menu's ordering idiom) plus the unpin, over
menu rows rather than drag & drop — dragging inside a horizontal, scrolling
Carousel fights the scroll, and menu rows are keyboard-reachable for free. The
reorder is optimistic on the cached payload and re-asks the server on failure
rather than showing an order that was never accepted.

The exhausted shelf tile (a pinned channel with nothing unwatched left) is
`aria-disabled`, not `disabled`: measured in Chromium, a disabled button still
receives contextmenu and pointerdown, but it loses focus — and with it Shift+F10,
the only keyboard route to the menu it most needs.

Verified end to end in the browser against the live account: all five pin kinds,
the reorder (persisted across a reload), the unpin, and the honest Unpin label on
a resume tile that is already on the shelf.

frontend/src/components/VideoCard.tsx

@@ -385,6 +385,7 @@ function VideoCard({
   onResetState,
   onToggleSave,
   onOpen,
+  menuProps,
 }: {
   video: Video;
   view: FeedView;
@@ -394,6 +395,12 @@ function VideoCard({
   onResetState?: (id: string) => void;
   onToggleSave: (id: string, saved: boolean) => void;
   onOpen?: (v: Video, startAt?: number | null) => void;
+  /** Right-click / long-press props for the LIST's one context menu (E24 S3 — the comfort pin).
+   *  A FUNCTION, not the already-built props object: `useContextMenu.triggerProps` is stable across
+   *  renders while its return value is a fresh object every call, and a fresh object prop would
+   *  blow past this component's memo for every card in the virtualized feed on every parent
+   *  render. The card calls it with the video it already has. */
+  menuProps?: (v: Video) => Record<string, unknown>;
 }) {
   const { t, i18n } = useTranslation();
   const { openChannel } = useNavigationActions();
@@ -521,6 +528,7 @@ function VideoCard({
         <div
           data-testid="video-card"
           data-video-id={video.id}
+          {...menuProps?.(video)}
           className={clsx(rowShell, "flex items-center gap-3 px-3 py-2", watched && "opacity-55")}
         >
           {/* Actions lead: this is where the eye already is (the title is the thing you read), so
@@ -583,6 +591,7 @@ function VideoCard({
       <div
         data-testid="video-card"
         data-video-id={video.id}
+        {...menuProps?.(video)}
         className={clsx(rowShell, "flex gap-3 p-2", watched && "opacity-55")}
       >
         <Thumb
@@ -616,6 +625,7 @@ function VideoCard({
     <div
       data-testid="video-card"
       data-video-id={video.id}
+      {...menuProps?.(video)}
       className={clsx(
         "cv-card group glass-card glass-hover rounded-2xl transition-all duration-150",
         "flex flex-col",