feat(design): a Plex title's one action list (C1) — the poster's "…", details and the pin in its menu (E28 S3e2)

Every Plex poster list (library, Discover rails, person, show, season, collection, Home's rails)
now opens one menu per list from the right-click, the long-press, Shift+F10 and the card's "…":
play/open, watched, add to playlist, media info, copy title, the pin (usePlexCardActions +
PlexMenu, replacing the pin-only PlexPinMenu). The card keeps its state at rest and shows
watched / add to playlist / "…" on its picture on hover (ui/reveal.ts, shared with the video
card); on touch the toggles are gone and a 44px "…" sits beside the title, while the watched pill
stays. The hover ⓘ left the card; an episode's add button moved from its caption to the hover
row. Seasons get their own short menu (open, watched, add, copy), labelled "Open season" (the
card's overlay said "Open show"). Related shows are ordinary poster cards now. A collection's
admin "Remove" X moved into its menu, still behind the confirmation. The collection grid is two
columns on a phone. The unused .reveal-idle rule is gone.

frontend/src/components/VideoCard.tsx

@@ -26,6 +26,7 @@ import { IconButton } from "./ui/IconButton";
 import { Button } from "./ui/Button";
 import { SURFACE } from "./ui/surfaces";
 import { MoreButton } from "./ui/MoreButton";
+import { HOVER_REVEAL, HOVER_YIELD } from "./ui/reveal";
 
 /** The "…" that opens the video's action list, and whether its menu is the open one. */
 type More = { props: Record<string, unknown>; open: boolean };
@@ -100,10 +101,6 @@ function Actions({
   );
 }
 
-// The thumbnail's hover chrome: shown on hover or keyboard focus on a mouse, removed on touch.
-const HOVER_REVEAL =
-  "reveal-hover opacity-0 group-hover:opacity-100 group-focus-within:opacity-100 transition-opacity";
-
 // Plain left-click opens the in-app player (the experiment); Ctrl/Cmd/middle-click
 // keep the native "open youtube.com in a new tab" behavior via the underlying href.
 function openInApp(
@@ -252,7 +249,7 @@ function Thumb({
             className={clsx(
               "absolute bottom-1.5 right-1.5 bg-black/80 text-white text-2xs font-medium px-1.5 py-0.5 rounded-sm",
               // The hover row takes this corner; the duration steps aside while it shows.
-              bar && "transition-opacity group-hover:opacity-0 group-focus-within:opacity-0",
+              bar && HOVER_YIELD,
             )}
           >
             {formatDuration(video.duration_seconds)}