refactor(pins): drop the unused ComfortPinMenu and the comment that described it

Every surface composes the pin row into its object's one action list (E28 C1); the pin-only menu
had no caller left. Also un-exports isStandInFocus, which only its own file reads since H1.

frontend/src/components/ComfortPinMenu.tsx

@@ -1,38 +0,0 @@
-import { useTranslation } from "react-i18next";
-
-import { useComfortPin, type PinTarget } from "./comfortPin";
-import { ContextMenu } from "./ui/ContextMenu";
-import { type ContextMenuController } from "./ui/useContextMenu";
-
-// The menu SURFACE for the comfort-shelf pin (E24 S3). Split from `comfortPin.tsx` for the same
-// reason `ContextMenu.tsx` is split from `useContextMenu.ts`: a file that exports components and
-// nothing else keeps react-refresh working for every surface that imports it.
-
-/**
- * The whole right-click menu for a surface whose only context action is the pin — the card grids and
- * rails. Render ONE per list, outside the rows (see `ui/ContextMenu`), and spread
- * `menu.triggerProps` on each row.
- *
- * `target` maps the row the user right-clicked to its pin; `title` names it in the confirmation
- * toast. Both come from the call site because only it knows what its rows are.
- */
-export function ComfortPinMenu<T>({
-  menu,
-  target,
-  title,
-}: {
-  menu: ContextMenuController<T>;
-  target: (row: T) => PinTarget | null;
-  title: (row: T) => string;
-}) {
-  const { t } = useTranslation();
-  const pin = useComfortPin(menu.open);
-  const row = menu.target;
-  return (
-    <ContextMenu
-      menu={menu}
-      ariaLabel={t("home.pin.menu")}
-      items={row ? pin.item(target(row), title(row)) : []}
-    />
-  );
-}

frontend/src/components/comfortPin.tsx

@@ -15,13 +15,12 @@ import { type ActionMenuItem } from "./ui/ActionMenu";
 // shown — a video, a channel, a playlist, a Plex show or movie: you decide something is comfort media
 // while you are watching it. (Locked decision 3: an episode, a season and a person are not pin kinds,
 // so their cards and strips carry no pin.) This file is the one place the pin lives; every surface
-// composes the same `ActionMenuItem` into the menu it already has (`Playlists`, `PlaylistsRail`) or
-// mounts the `ComfortPinMenu` wrapper when it has none.
+// composes the same `ActionMenuItem` into its object's ONE action list (E28 C1): the video, Plex and
+// channel actions (`useVideoActions`, `usePlexCardActions`, `Channels`), the playlist rail and page,
+// and Home's shelves. There is no pin-only menu any more.
 //
 // Feature layer, not `components/ui/`: it speaks a domain API slice, which the platform boundary
-// (eslint `no-restricted-imports`) forbids a `ui/` primitive from doing. The MENU SURFACE that
-// renders this item lives in `ComfortPinMenu.tsx` — the same hook/component split, for the same
-// react-refresh reason, as `useContextMenu.ts` beside `ContextMenu.tsx`.
+// (eslint `no-restricted-imports`) forbids a `ui/` primitive from doing.
 
 /** What the API needs to pin something: the kind, and the id the rest of the API already speaks for
  *  that kind (a video id, a channel id, a Plex `rating_key`, a playlist id). Mirrors

frontend/src/lib/useFocusKeeper.ts

@@ -52,7 +52,7 @@ export function focusNeighbour(el: HTMLElement): boolean {
 let standIn: HTMLElement | null = null;
 
 /** Whether `el` holds the focus only because the keeper put it there. */
-export function isStandInFocus(el: Element | null): boolean {
+function isStandInFocus(el: Element | null): boolean {
   return el !== null && el === standIn;
 }