fix(ui): stable shelf-card menu triggers, a named Button by type, true layout comments

- Home's rail handed each card a fresh `() => menu.triggerProps(c)` per
  render, defeating memo(VideoCard) on every tile whenever the menu's own
  state changed. `useItemTriggers` (ui/useContextMenu) keeps one trigger per
  item, index-aligned; tested for identity across renders.
- The Button accessible-name union had one hole: `<Button icon={…} />` with
  no children and no size typechecked into a nameless button. A textful
  button now needs children or a name; pinned with @ts-expect-error.
- comfortPin's header said the pin belongs "on every card and row", which
  the code never meant (an episode, a season, a person are not pin kinds).
  It now says what is pinnable — and the show page's Related strip, whose
  shows ARE pinnable, gets the pin menu it was missing (and a rem width).
- gridColumns / feedView / VirtualGrid claimed layouts 1024–2560 are
  "byte-identical" under the column cap; the small cards are capped at 2560
  with the filter rail collapsed. The comments say so.

frontend/src/components/comfortPin.tsx

@@ -11,11 +11,12 @@ import { type ActionMenuItem } from "./ui/ActionMenu";
 
 // E24 S3 — "put this on my comfort shelf", from wherever you happen to be looking at the thing.
 //
-// The shelf is the Home surface's object, but the GESTURE belongs on every card and row in the app:
-// you decide something is comfort media while you are watching it, not while you are on a page that
-// already lists it. So this file is the one place the pin lives, and every surface composes the same
-// `ActionMenuItem` into the menu it already has (`Playlists`, `PlaylistsRail`) or mounts the
-// `ComfortPinMenu` wrapper when it has none.
+// The shelf is the Home surface's object, but the GESTURE belongs wherever a pinnable thing is
+// 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.
 //
 // 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