feat(web): shared collection header, Play and Shuffle, and the centred page column (M494)

- CollectionHeader holds cover, title, facts, then Play and Shuffle, for
  album and playlist. The playlist page gains Play and Shuffle; it had
  neither. The cover uses the shared Cover component, so the playlist
  header also gets the fallback image.
- PlayActions is the one Play and Shuffle pair: filled Play, outlined
  Shuffle, on album, playlist and artist pages (operator, 2026-10-08).
  The artist page's round icon button said Play but shuffled; Play now
  keeps the server's order, and Shuffle shuffles.
- PageColumn is the playlist page's centred column, now used by album,
  playlist, Liked, History and Search → Tracks.
- The playlist page builds its queue with playlistTrackToRef, the shared
  converter, in place of its own copy. Its copy skipped only removed
  tracks, so a missing file (#2527) could still be queued from there.
- shuffled() in lib/utils is the one shuffle, replacing three private
  copies (album page, artist page, ArtistCard).
- The album's refetch error now uses text-error-fg. `text-oxblood` is
  not a colour in the theme, so it never rendered.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/lib/components/HistoryRow.svelte

@@ -3,6 +3,7 @@
   import { playQueue } from '#lib/player/store.svelte.js';
   import { coverUrl } from '#lib/media/covers.js';
   import TrackListRow from './TrackListRow.svelte';
+  import Cover from './Cover.svelte';
 
   let { event } = $props<{ event: HistoryEvent }>();
 
@@ -50,12 +51,9 @@
   onActivate={handleClick}
 >
   {#snippet lead()}
-    <img
-      src={coverUrl(event.track.album_id)}
-      alt=""
-      class="h-8 w-8 rounded object-cover"
-      loading="lazy"
-    />
+    <span class="block h-8 w-8 overflow-hidden rounded">
+      <Cover src={coverUrl(event.track.album_id)} />
+    </span>
   {/snippet}
 
   {#snippet trailing()}