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/ArtistCard.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+  import { shuffled } from '#lib/utils/shuffle.js';
   import type { ArtistRef, TrackRef } from '#lib/api/types.js';
   import { api } from '#lib/api/client.js';
   import { playQueue, enqueueTracks } from '#lib/player/store.svelte.js';
@@ -12,21 +13,12 @@
 
   let queueing = $state(false);
 
-  function shuffle<T>(items: T[]): T[] {
-    const arr = items.slice();
-    for (let i = arr.length - 1; i > 0; i--) {
-      const j = Math.floor(Math.random() * (i + 1));
-      [arr[i], arr[j]] = [arr[j], arr[i]];
-    }
-    return arr;
-  }
-
   async function onPlayClick(e: MouseEvent) {
     e.preventDefault();
     e.stopPropagation();
     const tracks = await api.get<TrackRef[]>(`/api/artists/${artist.id}/tracks`);
     if (tracks.length === 0) return;
-    playQueue(shuffle(tracks), 0);
+    playQueue(shuffled(tracks), 0);
   }
 
   async function onAddToQueue(e: MouseEvent) {

web/src/lib/components/CollectionHeader.svelte

@@ -0,0 +1,60 @@
+<script lang="ts">
+  // The header of every page that is one collection of tracks, album and
+  // playlist (milestone 494): cover, title, a line or two of facts, then
+  // Play and Shuffle (PlayActions).
+  import type { Snippet } from 'svelte';
+  import PlayActions from './PlayActions.svelte';
+  import Cover from './Cover.svelte';
+
+  let {
+    title,
+    coverUrl,
+    coverAlt = '',
+    playDisabled = false,
+    onPlay,
+    onShuffle,
+    titleExtra,
+    tools,
+    children,
+    actions
+  }: {
+    title: string;
+    coverUrl: string | null | undefined;
+    coverAlt?: string;
+    playDisabled?: boolean;
+    onPlay: () => void;
+    onShuffle: () => void;
+    /** Beside the title, e.g. the album's like button. */
+    titleExtra?: Snippet;
+    /** Top right: refresh, link, edit, delete. */
+    tools?: Snippet;
+    /** The facts under the title. */
+    children?: Snippet;
+    /** After Play and Shuffle, e.g. an admin's Refetch cover. */
+    actions?: Snippet;
+  } = $props();
+</script>
+
+<header class="mb-6 flex items-start gap-4">
+  <div class="h-32 w-32 shrink-0 overflow-hidden rounded-md md:h-40 md:w-40">
+    <Cover src={coverUrl ?? undefined} alt={coverAlt} />
+  </div>
+
+  <div class="min-w-0 flex-1 space-y-2">
+    <div class="flex items-start gap-3">
+      <h1 class="min-w-0 truncate font-display text-2xl font-medium text-text-primary">{title}</h1>
+      {#if titleExtra}{@render titleExtra()}{/if}
+      {#if tools}
+        <div class="ml-auto flex shrink-0 items-center gap-1">{@render tools()}</div>
+      {/if}
+    </div>
+
+    {#if children}{@render children()}{/if}
+
+    <div class="pt-1">
+      <PlayActions name={title} disabled={playDisabled} {onPlay} {onShuffle}>
+        {#if actions}{@render actions()}{/if}
+      </PlayActions>
+    </div>
+  </div>
+</header>

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()}

web/src/lib/components/HistoryRow.test.ts

@@ -1,6 +1,5 @@
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent } from '@testing-library/svelte';
-import HistoryRow from './HistoryRow.svelte';
 import type { HistoryEvent } from '#lib/api/history.js';
 import { makeTrack } from '#test-utils/fixtures/track.js';
 import { emptyLikesMock } from '../../test-utils/mocks/likes';
@@ -27,6 +26,10 @@ vi.mock('#lib/api/likes.js', () => emptyLikesMock());
 
 vi.mock('#lib/api/quarantine.js', () => emptyQuarantineMock());
 
+// Imported after the mocks: the component pulls in LikeButton, whose
+// mocked module must already be initialised.
+import HistoryRow from './HistoryRow.svelte';
+
 const sampleTrack = makeTrack({
   title: 'Song Title',
   album_title: 'Album',

web/src/lib/components/PageColumn.svelte

@@ -0,0 +1,14 @@
+<script lang="ts">
+  // The centred column every track-list page sits in: album, playlist,
+  // Liked, History and Search → Tracks (milestone 494). The playlist page
+  // had it alone from May 2026; the operator picked it as the page shape
+  // on 2026-10-08. Shelf and grid pages (Home, Library, Discover, Artist,
+  // Search) stay full width, since a narrow column would cost them cards.
+  import type { Snippet } from 'svelte';
+
+  let { children }: { children: Snippet } = $props();
+</script>
+
+<div class="mx-auto w-full max-w-4xl space-y-4 px-4 py-6">
+  {@render children()}
+</div>

web/src/lib/components/PlayActions.svelte

@@ -0,0 +1,53 @@
+<script lang="ts">
+  // Play and Shuffle, the same on every page that has them: album,
+  // playlist and artist (milestone 494). Play is filled and Shuffle
+  // outlined. The fill is the accent: the operator's call on 2026-10-08,
+  // made with the house rule against accent on action buttons stated to
+  // them.
+  import type { Snippet } from 'svelte';
+  import { Play, Shuffle } from 'lucide-svelte';
+
+  let {
+    name,
+    disabled = false,
+    onPlay,
+    onShuffle,
+    children
+  }: {
+    /** What is played, for the buttons' accessible names. */
+    name: string;
+    disabled?: boolean;
+    onPlay: () => void;
+    onShuffle: () => void;
+    /** Further actions after Shuffle. */
+    children?: Snippet;
+  } = $props();
+</script>
+
+<div class="flex flex-wrap items-center gap-2">
+  <button
+    type="button"
+    aria-label={`Play ${name}`}
+    onclick={onPlay}
+    {disabled}
+    class="flex items-center gap-2 rounded-md bg-accent px-4 py-2 text-sm font-medium
+           text-text-primary hover:opacity-90 focus-visible:ring-2 focus-visible:ring-accent
+           disabled:opacity-50"
+  >
+    <Play size={16} strokeWidth={1.5} fill="currentColor" />
+    Play
+  </button>
+  <button
+    type="button"
+    aria-label={`Shuffle ${name}`}
+    onclick={onShuffle}
+    {disabled}
+    class="flex items-center gap-2 rounded-md border border-border bg-surface px-4 py-2
+           text-sm font-medium text-text-primary hover:border-accent
+           focus-visible:ring-2 focus-visible:ring-accent disabled:opacity-50"
+  >
+    <Shuffle size={16} strokeWidth={1.5} />
+    Shuffle
+  </button>
+  {#if children}{@render children()}{/if}
+</div>

web/src/lib/utils/shuffle.ts

@@ -0,0 +1,14 @@
+/**
+ * A shuffled copy of `items` (Fisher–Yates). The input is not touched.
+ *
+ * The one copy for every Shuffle control: the album and playlist headers
+ * and the artist card's play button each had their own before this.
+ */
+export function shuffled<T>(items: readonly T[]): T[] {
+  const arr = items.slice();
+  for (let i = arr.length - 1; i > 0; i--) {
+    const j = Math.floor(Math.random() * (i + 1));
+    [arr[i], arr[j]] = [arr[j], arr[i]];
+  }
+  return arr;
+}

web/src/routes/albums/[id]/+page.svelte

@@ -1,17 +1,18 @@
 <script lang="ts">
-  import { Play, Shuffle } from 'lucide-svelte';
+  import PageColumn from '#lib/components/PageColumn.svelte';
   import { page } from '$app/state';
   import { createAlbumQuery } from '#lib/api/queries.js';
   import { qk } from '#lib/api/queries.js';
   import { pageTitle } from '#lib/branding.js';
   import TrackRow from '#lib/components/TrackRow.svelte';
   import TrackList from '#lib/components/TrackList.svelte';
+  import CollectionHeader from '#lib/components/CollectionHeader.svelte';
+  import { shuffled } from '#lib/utils/shuffle.js';
   import LibrarySkeleton from '#lib/components/LibrarySkeleton.svelte';
   import ApiErrorBanner from '#lib/components/ApiErrorBanner.svelte';
   import LikeButton from '#lib/components/LikeButton.svelte';
   import { useDelayed } from '#lib/utils/useDelayed.svelte.js';
   import { formatDuration } from '#lib/media/duration.js';
-  import { FALLBACK_COVER } from '#lib/media/covers.js';
   import type { ApiError } from '#lib/api/client.js';
   import { playQueue } from '#lib/player/store.svelte.js';
   import { user } from '#lib/auth/store.svelte.js';
@@ -28,21 +29,8 @@
     query.isError && (query.error as unknown as ApiError | undefined)?.code === 'not_found'
   );
 
-  function onCoverError(e: Event) {
-    (e.currentTarget as HTMLImageElement).src = FALLBACK_COVER;
-  }
-
   let isStartingPlay = $state(false);
 
-  function shuffleArr<T>(items: T[]): T[] {
-    const arr = items.slice();
-    for (let i = arr.length - 1; i > 0; i--) {
-      const j = Math.floor(Math.random() * (i + 1));
-      [arr[i], arr[j]] = [arr[j], arr[i]];
-    }
-    return arr;
-  }
-
   function onPlay() {
     const data = query.data;
     if (isStartingPlay || !data || data.tracks.length === 0) return;
@@ -59,7 +47,7 @@
     if (isStartingPlay || !data || data.tracks.length === 0) return;
     isStartingPlay = true;
     try {
-      playQueue(shuffleArr(data.tracks), 0);
+      playQueue(shuffled(data.tracks), 0);
     } finally {
       isStartingPlay = false;
     }
@@ -92,7 +80,7 @@
   <title>{pageTitle(query.data?.title ? `Album · ${query.data.title}` : 'Album')}</title>
 </svelte:head>
 
-<div class="space-y-6">
+<PageColumn>
   {#if notFound}
     <div role="alert" class="rounded border border-border bg-surface p-4">
       <p>Album not found.</p>
@@ -111,91 +99,68 @@
       ← {album.artist_name}
     </a>
 
-    <header class="flex flex-col gap-4 md:flex-row md:items-end">
-      <img
-        src={album.cover_url}
-        alt={album.title}
-        class="h-60 w-60 rounded object-cover"
-        loading="lazy"
-        onerror={onCoverError}
-      />
-      <div class="flex-1 space-y-2">
-        <div class="flex items-center gap-3">
-          <h1 class="font-display text-2xl font-medium text-text-primary">{album.title}</h1>
-          <LikeButton entityType="album" entityId={album.id} size="lg" />
-        </div>
-        <p>
-          <a href={`/artists/${album.artist_id}`} class="hover:underline">{album.artist_name}</a>
+    <CollectionHeader
+      title={album.title}
+      coverUrl={album.cover_url}
+      coverAlt={album.title}
+      playDisabled={isStartingPlay || album.tracks.length === 0}
+      {onPlay}
+      {onShuffle}
+    >
+      {#snippet titleExtra()}
+        <LikeButton entityType="album" entityId={album.id} size="lg" />
+      {/snippet}
+      <p>
+        <a href={`/artists/${album.artist_id}`} class="hover:underline">{album.artist_name}</a>
+      </p>
+      <!-- Year and genre are quick-jumps into the browse axes (#367): from
+           an album you like, one click to everything else from that year or
+           in that genre. -->
+      {#if album.year}
+        <p class="text-sm">
+          <a href={`/library/years?y=${album.year}`} class="text-accent-fg hover:underline">
+            {album.year}
+          </a>
         </p>
-        <!-- Year and genre are quick-jumps into the browse axes (#367): from
-             an album you like, one click to everything else from that year or
-             in that genre. -->
-        {#if album.year}
-          <p class="text-sm">
-            <a href={`/library/years?y=${album.year}`} class="text-accent-fg hover:underline">
-              {album.year}
-            </a>
-          </p>
-        {/if}
-        {#if album.genres?.length}
-          <ul class="flex flex-wrap gap-1.5">
-            {#each album.genres as genre (genre)}
-              <li>
-                <a
-                  href={`/library/genres?g=${encodeURIComponent(genre)}`}
-                  class="inline-block rounded-full border border-border px-2.5 py-0.5 text-xs
-                         text-text-secondary hover:bg-surface-hover hover:text-text-primary
-                         focus-visible:ring-2 focus-visible:ring-accent"
-                >
-                  {genre}
-                </a>
-              </li>
-            {/each}
-          </ul>
-        {/if}
-        <p class="text-sm text-text-secondary">
-          {album.track_count} {album.track_count === 1 ? 'track' : 'tracks'}
-          · {formatDuration(album.duration_sec)}
-        </p>
-        <div class="flex items-center gap-2 pt-2">
+      {/if}
+      {#if album.genres?.length}
+        <ul class="flex flex-wrap gap-1.5">
+          {#each album.genres as genre (genre)}
+            <li>
+              <a
+                href={`/library/genres?g=${encodeURIComponent(genre)}`}
+                class="inline-block rounded-full border border-border px-2.5 py-0.5 text-xs
+                       text-text-secondary hover:bg-surface-hover hover:text-text-primary
+                       focus-visible:ring-2 focus-visible:ring-accent"
+              >
+                {genre}
+              </a>
+            </li>
+          {/each}
+        </ul>
+      {/if}
+      <p class="text-sm text-text-secondary">
+        {album.track_count} {album.track_count === 1 ? 'track' : 'tracks'}
+        · {formatDuration(album.duration_sec)}
+      </p>
+      {#snippet actions()}
+        {#if isAdmin}
           <button
             type="button"
-            aria-label={`Play ${album.title}`}
-            onclick={onPlay}
-            disabled={isStartingPlay || album.tracks.length === 0}
-            class="flex items-center gap-2 rounded-md bg-accent px-4 py-2 text-sm font-medium text-text-primary hover:opacity-90 focus-visible:ring-2 focus-visible:ring-accent disabled:opacity-50"
+            onclick={onRefetchCover}
+            disabled={refetching}
+            aria-label={`Refetch cover for ${album.title}`}
+            title={album.cover_art_source === 'none' ? 'No cover found previously — try again' : 'Refetch from MusicBrainz'}
+            class="flex items-center gap-2 rounded-md border border-border bg-surface px-3 py-2 text-sm font-medium text-text-secondary hover:border-accent disabled:opacity-50"
           >
-            <Play size={16} strokeWidth={1.5} fill="currentColor" />
-            Play
+            Refetch cover
           </button>
-          <button
-            type="button"
-            aria-label={`Shuffle ${album.title}`}
-            onclick={onShuffle}
-            disabled={isStartingPlay || album.tracks.length === 0}
-            class="flex items-center gap-2 rounded-md border border-border bg-surface px-4 py-2 text-sm font-medium text-text-primary hover:border-accent focus-visible:ring-2 focus-visible:ring-accent disabled:opacity-50"
-          >
-            <Shuffle size={16} strokeWidth={1.5} />
-            Shuffle
-          </button>
-          {#if isAdmin}
-            <button
-              type="button"
-              onclick={onRefetchCover}
-              disabled={refetching}
-              aria-label={`Refetch cover for ${album.title}`}
-              title={album.cover_art_source === 'none' ? 'No cover found previously — try again' : 'Refetch from MusicBrainz'}
-              class="flex items-center gap-2 rounded-md border border-border bg-surface px-3 py-2 text-sm font-medium text-text-secondary hover:border-accent disabled:opacity-50"
-            >
-              Refetch cover
-            </button>
-          {/if}
-          {#if refetchError}
-            <span class="text-sm text-oxblood">{refetchError}</span>
-          {/if}
-        </div>
-      </div>
-    </header>
+        {/if}
+        {#if refetchError}
+          <span class="text-sm text-error-fg">{refetchError}</span>
+        {/if}
+      {/snippet}
+    </CollectionHeader>
 
     {#if album.tracks.length === 0}
       <p class="text-text-secondary">This album has no tracks.</p>
@@ -207,4 +172,4 @@
       </TrackList>
     {/if}
   {/if}
-</div>
+</PageColumn>

web/src/routes/artists/[id]/+page.svelte

@@ -1,5 +1,6 @@
 <script lang="ts">
-  import { Play } from 'lucide-svelte';
+  import PlayActions from '#lib/components/PlayActions.svelte';
+  import { shuffled } from '#lib/utils/shuffle.js';
   import { page } from '$app/state';
   import {
     createArtistQuery,
@@ -36,31 +37,25 @@
     query.isError && (query.error as unknown as ApiError | undefined)?.code === 'not_found'
   );
 
-  // Mirrors ArtistCard's play overlay: fetch every track for the artist
-  // (server already honours per-user lidarr_quarantine), shuffle client-side,
-  // start the queue. Bypassed when the artist has nothing to play.
-  function shuffle<T>(items: T[]): T[] {
-    const arr = items.slice();
-    for (let i = arr.length - 1; i > 0; i--) {
-      const j = Math.floor(Math.random() * (i + 1));
-      [arr[i], arr[j]] = [arr[j], arr[i]];
-    }
-    return arr;
-  }
-
+  // Fetch every track for the artist (the server already honours per-user
+  // lidarr_quarantine) and start the queue, in the server's order for Play
+  // and shuffled for Shuffle. Bypassed when the artist has nothing to play.
   let isStartingPlay = $state(false);
 
-  async function onPlay() {
+  async function start(order: (tracks: TrackRef[]) => TrackRef[]) {
     if (isStartingPlay || !id) return;
     isStartingPlay = true;
     try {
       const tracks = await api.get<TrackRef[]>(`/api/artists/${id}/tracks`);
       if (tracks.length === 0) return;
-      playQueue(shuffle(tracks), 0);
+      playQueue(order(tracks), 0);
     } finally {
       isStartingPlay = false;
     }
   }
+
+  const onPlay = () => start((tracks) => tracks);
+  const onShuffle = () => start(shuffled);
 </script>
 
 <svelte:head>
@@ -108,16 +103,15 @@
             {/each}
           </ul>
         {/if}
+        <div class="mt-3">
+          <PlayActions
+            name={detail.name}
+            disabled={isStartingPlay || detail.album_count === 0}
+            {onPlay}
+            {onShuffle}
+          />
+        </div>
       </div>
-      <button
-        type="button"
-        aria-label={`Play ${detail.name}`}
-        onclick={onPlay}
-        disabled={isStartingPlay || detail.album_count === 0}
-        class="flex h-12 w-12 items-center justify-center rounded-full bg-accent text-text-primary shadow-sm transition-transform hover:scale-105 focus-visible:ring-2 focus-visible:ring-accent disabled:opacity-50 disabled:hover:scale-100"
-      >
-        <Play size={24} strokeWidth={1.5} fill="currentColor" class="ml-0.5" />
-      </button>
     </header>
 
     {#if detail.albums.length === 0}

web/src/routes/artists/[id]/artist.test.ts

@@ -1,8 +1,10 @@
 import { afterEach, beforeEach, describe, expect, test, vi } from 'vitest';
-import { render, screen } from '@testing-library/svelte';
+import { render, screen, fireEvent, waitFor } from '@testing-library/svelte';
 import { flushSync } from 'svelte';
 import { mockQuery } from '../../../test-utils/query';
 import { emptyLikesMock } from '../../../test-utils/mocks/likes';
+import { apiClientMock } from '../../../test-utils/mocks/client';
+import { makeTracks } from '#test-utils/fixtures/track.js';
 import type { ArtistDetail, AlbumRef } from '#lib/api/types.js';
 
 const state = vi.hoisted(() => ({ pageParams: { id: 'abc' } as Record<string, string> }));
@@ -23,7 +25,20 @@ vi.mock('#lib/api/queries.js', () => ({
 
 vi.mock('#lib/api/likes.js', () => emptyLikesMock());
 
+vi.mock('#lib/api/client.js', () => apiClientMock());
+
+vi.mock('#lib/player/store.svelte.js', () => ({
+  playQueue: vi.fn(),
+  enqueueTrack: vi.fn(),
+  enqueueTracks: vi.fn(),
+  playRadio: vi.fn(),
+  playNext: vi.fn(),
+  player: { current: undefined }
+}));
+
 import ArtistPage from './+page.svelte';
+import { api } from '#lib/api/client.js';
+import { playQueue } from '#lib/player/store.svelte.js';
 import {
   createArtistQuery,
   createSimilarArtistsQuery,
@@ -132,4 +147,33 @@ describe('artist detail page', () => {
       vi.useRealTimers();
     }
   });
+
+  // Play and Shuffle are the shared PlayActions (milestone 494). Play keeps
+  // the server's order; before, the artist's only button was "Play" and it
+  // shuffled.
+  describe('Play and Shuffle', () => {
+    const detail: ArtistDetail = {
+      id: 'abc', name: 'Alice', sort_name: 'Alice', album_count: 1, cover_url: '',
+      albums: [album('a1', 'First', 2020)], genres: []
+    };
+    const tracks = makeTracks(5);
+
+    test('Play queues the artist in the server order', async () => {
+      (createArtistQuery as ReturnType<typeof vi.fn>).mockReturnValue(mockQuery({ data: detail }));
+      (api.get as ReturnType<typeof vi.fn>).mockResolvedValue(tracks);
+      render(ArtistPage);
+      await fireEvent.click(screen.getByRole('button', { name: 'Play Alice' }));
+      await waitFor(() => expect(playQueue).toHaveBeenCalledWith(tracks, 0));
+    });
+
+    test('Shuffle queues every track', async () => {
+      (createArtistQuery as ReturnType<typeof vi.fn>).mockReturnValue(mockQuery({ data: detail }));
+      (api.get as ReturnType<typeof vi.fn>).mockResolvedValue(tracks);
+      render(ArtistPage);
+      await fireEvent.click(screen.getByRole('button', { name: 'Shuffle Alice' }));
+      await waitFor(() => expect(playQueue).toHaveBeenCalled());
+      const [queued] = (playQueue as ReturnType<typeof vi.fn>).mock.calls[0];
+      expect(queued.map((t: { id: string }) => t.id).sort()).toEqual(tracks.map((t) => t.id).sort());
+    });
+  });
 });

web/src/routes/library/history/+page.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+  import PageColumn from '#lib/components/PageColumn.svelte';
   import { pageTitle } from '#lib/branding.js';
   import { createHistoryQuery } from '#lib/api/history.js';
   import { groupByDay } from '#lib/utils/dayGroup.js';
@@ -29,7 +30,7 @@
 
 <svelte:head><title>{pageTitle('Library · History')}</title></svelte:head>
 
-<div class="space-y-4">
+<PageColumn>
   <header class="flex flex-wrap items-end justify-between gap-3">
     <h1 class="font-display text-2xl font-medium text-text-primary">History</h1>
     {#if flatEvents.length > 0}
@@ -83,4 +84,4 @@
       <p class="py-2 text-center text-sm text-text-secondary">End of history</p>
     {/if}
   {/if}
-</div>
+</PageColumn>

web/src/routes/library/history/page.test.ts

@@ -1,6 +1,5 @@
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { render, screen } from '@testing-library/svelte';
-import HistoryPage from './+page.svelte';
 import type { HistoryEvent, HistoryResponse } from '#lib/api/history.js';
 import { makeTrack } from '#test-utils/fixtures/track.js';
 import { emptyLikesMock } from '../../../test-utils/mocks/likes';
@@ -63,6 +62,10 @@ vi.mock('#lib/branding.js', () => ({
   pageTitle: (s: string) => `Minstrel · ${s}`
 }));
 
+// Imported after the mocks: the component pulls in LikeButton, whose
+// mocked module must already be initialised.
+import HistoryPage from './+page.svelte';
+
 describe('library/history page', () => {
   beforeEach(() => {
     mockData = { pages: [] };

web/src/routes/library/liked/+page.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+  import PageColumn from '#lib/components/PageColumn.svelte';
   import { pageTitle } from '#lib/branding.js';
   import {
     createLikedTracksInfiniteQuery,
@@ -50,7 +51,7 @@
 
 <svelte:head><title>{pageTitle('Library · Liked')}</title></svelte:head>
 
-<div class="space-y-6">
+<PageColumn>
   <header class="flex flex-wrap items-end justify-between gap-3">
     <h1 class="text-2xl font-semibold">Liked</h1>
     {#if artists.length + albums.length + tracks.length > 0}
@@ -176,4 +177,4 @@
     {/if}
   </section>
   {/if}
-</div>
+</PageColumn>

web/src/routes/playlists/[id]/+page.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+  import PageColumn from '#lib/components/PageColumn.svelte';
   import { page } from '$app/state';
   import { goto } from '$app/navigation';
   import { untrack } from 'svelte';
@@ -7,6 +8,9 @@
   import { useQueryClient } from '@tanstack/svelte-query';
   import PlaylistTrackRow from '#lib/components/PlaylistTrackRow.svelte';
   import TrackList from '#lib/components/TrackList.svelte';
+  import CollectionHeader from '#lib/components/CollectionHeader.svelte';
+  import { playlistTrackToRef } from '#lib/playlists/playlistTrackToRef.js';
+  import { shuffled } from '#lib/utils/shuffle.js';
   import ApiErrorBanner from '#lib/components/ApiErrorBanner.svelte';
   import {
     createPlaylistQuery,
@@ -75,23 +79,30 @@
     }
   }
 
-  function onPlay(position: number) {
-    if (!playlistQuery?.data) return;
-    const data = playlistQuery.data;
-    // Skip rows where track_id is null (track was removed from library).
-    const live = data.tracks.filter((t) => t.track_id !== null).map(toTrackRef);
-    // Find which `live` index corresponds to the clicked position. Some
-    // positions in the original list may be unavailable (filtered out),
-    // so the index in the playable list != the playlist position.
-    const clickedTrackID = data.tracks.find((t) => t.position === position)?.track_id;
-    const startIdx = live.findIndex((t) => t.id === clickedTrackID);
+  // Every entry that can be played, in playlist order. playlistTrackToRef
+  // drops both kinds of dead entry, removed tracks and missing files
+  // (#2527), so neither is ever queued.
+  function playable(data: PlaylistDetail): { refs: TrackRef[]; positions: number[] } {
+    const refs: TrackRef[] = [];
+    const positions: number[] = [];
+    for (const row of data.tracks) {
+      const ref = playlistTrackToRef(row);
+      if (ref) {
+        refs.push(ref);
+        positions.push(row.position);
+      }
+    }
+    return { refs, positions };
+  }
+
+  function startQueue(data: PlaylistDetail, tracks: TrackRef[], startIdx: number) {
     // #968: a system playlist played from its detail page is tagged with its
     // source (so play_started advances the rotation, matching the home tile and
     // the Android detail screen) and gets the self-heal closure so a stale
     // snapshot re-pulls on total failure.
     const variant = data.system_variant;
     if (variant != null) {
-      playQueue(live, Math.max(0, startIdx), {
+      playQueue(tracks, Math.max(0, startIdx), {
         source: variant,
         refetch: systemPlaylistRefetch({
           variant,
@@ -100,30 +111,25 @@
         })
       });
     } else {
-      playQueue(live, Math.max(0, startIdx));
+      playQueue(tracks, Math.max(0, startIdx));
     }
   }
 
-  function toTrackRef(t: {
-    track_id: string | null;
-    album_id: string | null;
-    artist_id: string | null;
-    title: string;
-    album_title: string;
-    artist_name: string;
-    duration_sec: number;
-    stream_url: string | null;
-  }): TrackRef {
-    return {
-      id: t.track_id!,
-      title: t.title,
-      album_id: t.album_id ?? '',
-      album_title: t.album_title,
-      artist_id: t.artist_id ?? '',
-      artist_name: t.artist_name,
-      duration_sec: t.duration_sec,
-      stream_url: t.stream_url ?? ''
-    } as unknown as TrackRef;
+  function onPlay(position: number) {
+    if (!playlistQuery?.data) return;
+    const data = playlistQuery.data;
+    const { refs, positions } = playable(data);
+    startQueue(data, refs, positions.indexOf(position));
+  }
+
+  function onPlayAll() {
+    if (!playlistQuery?.data) return;
+    startQueue(playlistQuery.data, playable(playlistQuery.data).refs, 0);
+  }
+
+  function onShuffle() {
+    if (!playlistQuery?.data) return;
+    startQueue(playlistQuery.data, shuffled(playable(playlistQuery.data).refs), 0);
   }
 
   let editing = $state(false);
@@ -229,7 +235,7 @@
   <title>{pageTitle(playlistQuery?.data?.name ? `Playlist · ${playlistQuery.data.name}` : 'Playlist')}</title>
 </svelte:head>
 
-<div class="mx-auto max-w-4xl px-4 py-6">
+<PageColumn>
   {#if playlistQuery?.isPending}
     <p class="text-text-muted">Loading…</p>
   {:else if playlistQuery?.isError}
@@ -255,64 +261,64 @@
       </div>
     {/if}
     {#if !editing}
-      <header class="mb-6 flex items-start gap-4">
-        <div class="h-32 w-32 shrink-0 overflow-hidden rounded-md bg-surface-hover">
-          {#if pl.cover_url}
-            <img src={pl.cover_url} alt="" class="h-full w-full object-cover" />
+      <CollectionHeader
+        title={pl.name}
+        coverUrl={pl.cover_url}
+        playDisabled={!pl.tracks.some((t) => playlistTrackToRef(t) !== null)}
+        onPlay={onPlayAll}
+        {onShuffle}
+      >
+        {#if pl.description}
+          <p class="text-sm text-text-muted">{pl.description}</p>
+        {/if}
+        <p class="text-xs text-text-muted">
+          {pl.track_count} {pl.track_count === 1 ? 'track' : 'tracks'}
+          {#if pl.is_public}· public{:else}· private{/if}
+          {#if !isOwner}· by {pl.owner_username}{/if}
+        </p>
+        {#snippet tools()}
+          {#if pl.refreshable && pl.system_variant}
+            <button
+              type="button"
+              disabled={refreshingSystem}
+              onclick={() => onRefreshSystem(pl.system_variant as string)}
+              class="rounded-md border border-border px-3 py-1.5 text-sm text-text-muted hover:text-text-primary"
+              aria-label="Refresh playlist"
+            >
+              {refreshingSystem ? 'Refreshing…' : 'Refresh'}
+            </button>
           {/if}
-        </div>
-        <div class="min-w-0 flex-1">
-          <h1 class="truncate text-2xl font-medium text-text-primary">{pl.name}</h1>
-          {#if pl.description}
-            <p class="mt-1 text-sm text-text-muted">{pl.description}</p>
+          {#if isOwner && pl.is_public}
+            <button
+              type="button"
+              onclick={onCopyLink}
+              aria-label="Copy public link to this playlist"
+              title="Copy link"
+              class="rounded p-2 text-text-muted hover:bg-surface-hover hover:text-text-primary"
+            >
+              <LinkIcon size={16} strokeWidth={1} />
+            </button>
           {/if}
-          <p class="mt-2 text-xs text-text-muted">
-            {pl.track_count} {pl.track_count === 1 ? 'track' : 'tracks'}
-            {#if pl.is_public}· public{:else}· private{/if}
-            {#if !isOwner}· by {pl.owner_username}{/if}
-          </p>
-        </div>
-        {#if pl.refreshable && pl.system_variant}
-          <button
-            type="button"
-            disabled={refreshingSystem}
-            onclick={() => onRefreshSystem(pl.system_variant as string)}
-            class="rounded-md border border-border px-3 py-1.5 text-sm text-text-muted hover:text-text-primary"
-            aria-label="Refresh playlist"
-          >
-            {refreshingSystem ? 'Refreshing…' : 'Refresh'}
-          </button>
-        {/if}
-        {#if isOwner && pl.is_public}
-          <button
-            type="button"
-            onclick={onCopyLink}
-            aria-label="Copy public link to this playlist"
-            title="Copy link"
-            class="rounded p-2 text-text-muted hover:bg-surface-hover hover:text-text-primary"
-          >
-            <LinkIcon size={16} strokeWidth={1} />
-          </button>
-        {/if}
-        {#if isOwner}
-          <button
-            type="button"
-            onclick={startEdit}
-            aria-label="Edit playlist"
-            class="rounded p-2 text-text-muted hover:bg-surface-hover hover:text-text-primary"
-          >
-            <Pencil size={16} strokeWidth={1} />
-          </button>
-          <button
-            type="button"
-            onclick={submitDelete}
-            aria-label="Delete playlist"
-            class="rounded p-2 text-text-muted hover:bg-surface-hover hover:text-action-destructive"
-          >
-            <Trash2 size={16} strokeWidth={1} />
-          </button>
-        {/if}
-      </header>
+          {#if isOwner}
+            <button
+              type="button"
+              onclick={startEdit}
+              aria-label="Edit playlist"
+              class="rounded p-2 text-text-muted hover:bg-surface-hover hover:text-text-primary"
+            >
+              <Pencil size={16} strokeWidth={1} />
+            </button>
+            <button
+              type="button"
+              onclick={submitDelete}
+              aria-label="Delete playlist"
+              class="rounded p-2 text-text-muted hover:bg-surface-hover hover:text-action-destructive"
+            >
+              <Trash2 size={16} strokeWidth={1} />
+            </button>
+          {/if}
+        {/snippet}
+      </CollectionHeader>
     {:else}
       <section class="mb-6 rounded-md border border-border bg-surface p-4">
         <label class="block text-sm font-medium text-text-primary">
@@ -376,4 +382,4 @@
       </TrackList>
     {/if}
   {/if}
-</div>
+</PageColumn>

web/src/routes/playlists/[id]/playlist.test.ts

@@ -1,4 +1,4 @@
-import { describe, expect, test, vi } from 'vitest';
+import { afterEach, describe, expect, test, vi } from 'vitest';
 import { render, screen, fireEvent, waitFor } from '@testing-library/svelte';
 import { mockQuery } from '../../../test-utils/query';
 import { emptyQuarantineMock } from '../../../test-utils/mocks/quarantine';
@@ -45,6 +45,7 @@ vi.mock('#lib/api/quarantine.js', () => emptyQuarantineMock());
 
 import PlaylistDetailPage from './+page.svelte';
 import { createPlaylistQuery, deletePlaylist, refreshSystem } from '#lib/api/playlists.js';
+import { playQueue } from '#lib/player/store.svelte.js';
 
 const mockedQuery = createPlaylistQuery as ReturnType<typeof vi.fn>;
 
@@ -58,7 +59,45 @@ const ownDetail: PlaylistDetail = {
   ]
 };
 
+afterEach(() => vi.clearAllMocks());
+
 describe('Playlist detail page', () => {
+  // A missing file (#2527) stays in the list but is never queued: the
+  // page used to build its queue with its own converter, which only
+  // skipped removed tracks.
+  test('Play queues every playable entry and skips a missing file', async () => {
+    const withMissing: PlaylistDetail = {
+      ...ownDetail,
+      track_count: 3,
+      tracks: [
+        ...ownDetail.tracks,
+        { ...ownDetail.tracks[1], position: 2, track_id: 't3', title: 'C', stream_url: null, unavailable: true }
+      ]
+    };
+    mockedQuery.mockReturnValue(mockQuery({ data: withMissing }));
+    render(PlaylistDetailPage);
+    await fireEvent.click(screen.getByRole('button', { name: 'Play Mine' }));
+    const [queued, start] = (playQueue as ReturnType<typeof vi.fn>).mock.calls[0];
+    expect(queued.map((t: { id: string }) => t.id)).toEqual(['t1', 't2']);
+    expect(start).toBe(0);
+  });
+
+  test('clicking a row starts the queue at that track', async () => {
+    mockedQuery.mockReturnValue(mockQuery({ data: ownDetail }));
+    render(PlaylistDetailPage);
+    await fireEvent.click(screen.getByText('B'));
+    const [queued, start] = (playQueue as ReturnType<typeof vi.fn>).mock.calls.at(-1)!;
+    expect(queued[start].id).toBe('t2');
+  });
+
+  test('Shuffle queues the same playable entries', async () => {
+    mockedQuery.mockReturnValue(mockQuery({ data: ownDetail }));
+    render(PlaylistDetailPage);
+    await fireEvent.click(screen.getByRole('button', { name: 'Shuffle Mine' }));
+    const [queued] = (playQueue as ReturnType<typeof vi.fn>).mock.calls.at(-1)!;
+    expect(queued.map((t: { id: string }) => t.id).sort()).toEqual(['t1', 't2']);
+  });
+
   test('renders header + tracks for owner', () => {
     mockedQuery.mockReturnValue(mockQuery({ data: ownDetail }));
     render(PlaylistDetailPage);

web/src/routes/search/tracks/+page.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+  import PageColumn from '#lib/components/PageColumn.svelte';
   import { pageTitle } from '#lib/branding.js';
   import { page } from '$app/state';
   import { createSearchTracksInfiniteQuery } from '#lib/api/queries.js';
@@ -25,7 +26,7 @@
 
 <svelte:head><title>{pageTitle('Search · Tracks')}</title></svelte:head>
 
-<div class="space-y-4">
+<PageColumn>
   <header>
     <a href={`/search?q=${encodeURIComponent(q)}`} class="text-sm text-text-secondary hover:text-text-primary">
       ← Back to search
@@ -61,4 +62,4 @@
       </button>
     {/if}
   {/if}
-</div>
+</PageColumn>