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/lib/plexDetail.ts

@@ -42,6 +42,11 @@ export interface DetailFacts {
 
 export type AsideSection = "facts" | "keywords" | "crew";
 
+// The movie and the show page's poster. It keeps its 2:3 (self-start, never stretched to the row: the
+// second column beside the text runs taller than the poster), and a wide hero (the @container
+// panel at 64rem+) gives it a bigger rung, so it is not a stamp beside a full text column (E31).
+export const DETAIL_POSTER = "w-32 sm:w-44 @5xl:w-56";
+
 // The detail pages' second column (plexDetailAside, E31): which of its three sections — the TMDB facts,
 // keywords and key crew — have something to show, which the reader keeps on (three per-user prefs,
 // default ON, the same on the movie and the show page), and the toggles' flips.