fix(ui): the Plex detail poster keeps its 2:3, and a long crew shows its first names

The hero's grid row is as tall as the crew column beside the text, and the poster, a flex child,
stretched to it: a 2:3 picture drawn ~175x590 and cropped. It now aligns to the top, and a wide hero
gives the movie and show poster a bigger rung (w-56). The crew, the hero's tallest part, shows its
first 6 names and a 'Show N more' toggle; a list of 8 or fewer shows whole.

frontend/src/components/plexDetailUi.tsx

@@ -9,6 +9,7 @@ import {
   type LucideIcon,
 } from "lucide-react";
 import { useDismiss } from "../lib/useDismiss";
+import { DETAIL_POSTER } from "../lib/plexDetail";
 import { Button } from "./ui/Button";
 import { IconButton } from "./ui/IconButton";
 import { Pressable } from "./ui/Pressable";
@@ -239,7 +240,7 @@ export function DetailHero({
   posterDisabled,
   showPlayOverlay,
   onPosterClick,
-  posterSizeClass = "w-32 sm:w-44",
+  posterSizeClass = DETAIL_POSTER,
   customizeMenu,
   aside,
   children,