feat(explore): demote the album page's version selector to a disclosure

Choosing which pressing you are looking at is an advanced,
metadata-repair task, and it sat directly above the tracklist with a
heading, a `<select>` and a paragraph explaining how our clustering
picks a "standard version" by weighing release count, status and date.
That is a sentence about our own heuristic in the most valuable space
on the page.

It is now "Other versions of this album (N)" below the tracklist: a
real `<button aria-expanded aria-controls>` inside the heading that
names the section, with the body rendered unconditionally and toggled
with `hidden`, because `aria-controls` has to name an element that is
in the DOM. Both rules are `config-section`'s rather than new ones.
It is demoted, not removed — matching the wrong release is a real
problem and this is how it gets fixed.

**Two more blocks shared that slot and neither was guarded.** The
selector at least had `distinctTracklistCount() <= 1`; the
`Versions / Loading releases…` spinner and the `Versions / <error>`
block did not, so both took the primary position on every album
regardless of whether there was ever going to be a choice. The spinner
said what `renderTracklist` was already saying about the same fetch, so
it is gone. The error was the one `catalog-scope-notice` shows at the
top of the page with a retry — every path that sets `errorReleases`
also sets `catalogFailed`, the only route to `unavailable`.

That error is what made this a rewrite rather than a move.
`renderTracklist` returned `nothing` on `errorReleases` and leaned on
the selector's own block to have said it, and a control inside a
collapsed disclosure cannot be a page's error surface. The failure
belongs to the list that is missing because of it, so that is where it
is drawn.

**What must not be lost is which version is on screen.** The default is
what the header already describes, so saying it on every album would be
this issue's own complaint one size smaller. `defaultVersionKey` is the
test: a line appears above the tracklist only once someone has chosen
another, naming it and offering the way back. The ★ and the words "in
your library" survive unchanged inside the panel, and the panel does
not close when the selection changes — a panel that shuts on use cannot
be used twice.

The `<select>` also loses an `aria-label` of "Select release version"
that outranked its own visible `<label>Version</label>`, which is a
label not in the name.

Verified against the running app as well as the suite: the collapsed
page, the open panel, a chosen version and 390px width all read
correctly, and the shell still measures 390 in a 390 viewport.

Closes #17

.planning/NOTES.md

@@ -3534,3 +3534,49 @@ silent.** `artifactHasTotals` and `artifactHasCredits` are both correct
 and both mean a feature can ship, pass every test, and produce nothing
 for anybody without a single failure anywhere. Checking the *published
 file* is one query and is not implied by any tick in CI.
+
+## "Do I own this" has two answers in the schema, and one of them is a flag (2026-08-19)
+
+Decided while doing #38, and it outlives it because every future
+catalog surface has to pick one.
+
+`explore_index` carries both `in_library` and `local_artist_id` /
+`local_release_group_id` / `local_recording_id`. They are written by
+the same pass (`collectLibraryEntities`), so on a healthy database they
+agree, and the code read them as an OR — `inLibrary || localId > 0` —
+at eight call sites.
+
+They are not the same kind of thing:
+
+- **`local_*_id` is a fact with an owner.** Every query that sets one
+  joins `audio_files`, and `pruneStaleLocalCrossReferences` clears it
+  with an existence test that is a file test in all three cases. It is
+  the same rule `explore-album-details`'s `filePaths` implements, one
+  layer down and computed once per scan.
+- **`in_library` is a ratchet.** `upsertBatch` raises it with
+  `MAX(in_library, excluded.in_library)` and the prune is the only
+  thing that lowers it — gated on the local id being non-null, so a row
+  holding the flag *without* an id is a fixed point nothing can clear.
+  Filed as #118; it still drives search scoring, the popularity-floor
+  bypass and two Explore shelves, so routing the UI around it was not a
+  fix.
+
+What made the choice concrete rather than theoretical: on
+`explore-artist-details` the *same card* used both. The context menu
+gated Play on `localId > 0`; the badge used `inLibrary`. An album with
+the flag and no local row drew a green tick saying it was in your
+library, offered no Play, and — the request item being gated on *not*
+owned — offered no way to ask for it either.
+
+The rejected alternative is worth keeping: batching a real file lookup
+per screenful, the way `credit-store` coalesces. It would have answered
+for **recordings** (`GetFilePathsByRecordingMBIDs`) and most of the
+cards on these surfaces are release groups, so it would have made track
+rows strong, left album cards exactly where they were, and cost a new
+store. The batch that *was* worth adding is a different question —
+`GetAlbumsCompleteness`, "how much of this album is here", which no
+per-card flag can answer at all.
+
+The general point: **two columns that agree today are not one column.**
+Which of them a new surface reads should be decided by which one has
+something that can un-set it.

CLAUDE.md

@@ -1658,6 +1658,59 @@ not about plumbing — it says rows may be missing from the page
 altogether, which nothing on screen can show. (`explore-artist-details`
 still uses `loading`; it has no equivalent per-row signal.)
 
+**And that treatment is the app's, not the page's.**
+`utils/ownership.ts` is the rule written once, because it was written
+at eight call sites and so none of them had the whole of it: Explore's
+cards, `top-results-row` and the artist page's three card shapes all
+mixed owned and unowned with a small badge as the only difference, and
+the badge on the *owned* ones was a green tick — the mark on the common
+case this tracklist removed. Owned is plain and draws no badge at all;
+unowned is dimmed, says so in its accessible name, and keeps its
+request affordance; a partly-held album says how partly.
+
+Four things about it are load-bearing.
+
+**Ownership is `localId`, and `inLibrary` is deliberately not
+consulted.** The album page answers with `filePaths`, a real file per
+displayed track, and a card grid cannot afford that — but it does not
+need to, because `explore_index.local_*_id` is built by
+`collectLibraryEntities` from queries that every one join `audio_files`
+and cleared by `pruneStaleLocalCrossReferences`, whose existence test
+is a file test in all three cases. That is the same "ownership is a
+file" rule computed once per scan instead of once per screenful.
+`in_library` is written by the same pass, so the two agree in a healthy
+database, but it is a one-way ratchet
+(`MAX(in_library, excluded.in_library)`) whose only clearing pass is
+gated on a non-null local id: it cannot be un-set on its own (#118).
+One is a fact with an owner; the other is a flag that happens to agree.
+Both `explore-view` and `explore-artist-details` additionally kept a
+`libraryMBIDs` set that accumulated every MBID ever seen with the flag
+and cleared it never, in views that never unmount; both are gone.
+
+**The two answers used to sit on one card.**
+`renderReleaseMenuItems` gates Play on `release.localId > 0` while the
+badge used `inLibrary`, so an album with the flag and no local row drew
+a tick saying it was in your library, offered no Play, and — the
+request item being gated on *not* owned — offered no way to ask for it
+either. Any new surface that asks the question twice will reproduce it.
+
+**`aria-disabled` goes on rows and not on cards.** An unowned *row*
+cannot be activated; an unowned *card* still navigates to the catalog
+page for it, which is a perfectly good thing to do with something you
+do not own. The accessible name carries the state either way, which is
+why it is one helper and not a class.
+
+**The count is batched, not looked up.** `store/completeness-store.ts`
+is `credit-store` one question over: `request()` is per-card and
+coalesces a screenful into one `GetAlbumsCompleteness`, absence is
+cached as an answer (or the albums with no totals re-ask forever), and
+the whole cache is dropped on a scan, a retag or a removal rather than
+aged. `library-status.ts`'s `albumBadgeFor` is where that meets
+`Known`: a total that was never declared is a plain `in-library`, never
+a ring at 0%. One consequence in the badge itself — a `partial` badge
+is *actionable*, and a control named after its action alone dropped the
+count from the one state the ring exists for, so its name is both.
+
 **A partly-owned album draws the release, not the part.** Once the tags
 say nine of twelve, `buildLibraryEntry` shows the *catalog's* twelve
 with three dimmed, rather than the nine on disk — the missing tracks

frontend/src/components/explore-album-details/explore-album-details.ts

@@ -198,6 +198,28 @@ export class ExploreAlbumDetails extends LitElement implements ContextMenuHost {
     @state() private versionEntries: VersionEntry[] = [];
     /** Currently-selected dropdown entry (by VersionEntry.key). */
     @state() private selectedVersionKey: string = '';
+
+    /**
+     * The key `buildClusters` defaulted to, kept so the page can tell
+     * "this is what we picked for you" from "you went and chose this".
+     *
+     * Only the second needs saying out loud. With the selector demoted
+     * to a disclosure below the tracklist, a chosen version is the one
+     * case where the list on screen is not the one the header
+     * describes, and nothing else on the page would say so.
+     */
+    @state() private defaultVersionKey: string = '';
+
+    /**
+     * Whether the "Other versions" disclosure is open.
+     *
+     * Collapsed by default — choosing which pressing you are looking at
+     * is a metadata-repair task and does not belong above the
+     * tracklist. It is deliberately *not* closed when the selection
+     * changes: the user opened it to change something, and a panel that
+     * shuts on use cannot be used twice.
+     */
+    @state() private versionsOpen = false;
     @state() private coverArtURL = '';
 
     /**
@@ -523,7 +545,93 @@ export class ExploreAlbumDetails extends LitElement implements ContextMenuHost {
                 flex-shrink: 0;
             }
 
-            /* ── Version selector ── */
+            /* ── Other versions (a disclosure, below the tracklist) ── */
+            .versions {
+                margin-top: 24px;
+                border-top: 1px solid
+                    var(--yj-border-subtle, rgba(255, 255, 255, 0.08));
+                padding-top: 8px;
+            }
+
+            /* The heading exists so the section is reachable by heading
+             * navigation; the button inside it is the control. Its own
+             * type scale is the section header's, reduced — this is a
+             * footnote to the page, not a peer of the tracklist. */
+            .versions-heading {
+                margin: 0;
+                font-size: var(--yj-text-sm);
+                font-weight: 500;
+            }
+
+            .versions-toggle {
+                display: flex;
+                align-items: center;
+                gap: 8px;
+                width: 100%;
+                padding: 8px 2px;
+                background: none;
+                border: none;
+                color: var(--yj-text-secondary, #b3b3b3);
+                font: inherit;
+                text-align: left;
+                cursor: pointer;
+            }
+
+            .versions-toggle:hover {
+                color: var(--yj-text-primary, #fff);
+            }
+
+            .versions-toggle:focus-visible {
+                outline: 2px solid var(--yj-accent-text, #ffd43b);
+                outline-offset: 2px;
+                border-radius: 4px;
+            }
+
+            .versions-toggle wa-icon {
+                font-size: var(--yj-icon-xs, 11px);
+                transition: transform 0.2s ease;
+            }
+
+            .versions-toggle[aria-expanded='false'] wa-icon {
+                transform: rotate(-90deg);
+            }
+
+            .versions-intro {
+                margin: 0 0 10px;
+                font-size: var(--yj-text-xs);
+                color: var(--yj-text-tertiary, #888);
+                line-height: 1.4;
+            }
+
+            /* A line above the tracklist, and only after a deliberate
+             * choice — see renderChosenVersion. */
+            .chosen-version {
+                margin: 0 0 10px;
+                font-size: var(--yj-text-sm);
+                color: var(--yj-text-secondary, #b3b3b3);
+            }
+
+            .chosen-version strong {
+                color: var(--yj-text-primary, #fff);
+                font-weight: 600;
+            }
+
+            .chosen-version-reset {
+                background: none;
+                border: none;
+                padding: 0;
+                font: inherit;
+                color: var(--yj-accent-text, #ffd43b);
+                text-decoration: underline;
+                cursor: pointer;
+            }
+
+            .chosen-version-reset:focus-visible {
+                outline: 2px solid var(--yj-accent-text, #ffd43b);
+                outline-offset: 2px;
+                border-radius: 2px;
+            }
+
             .version-selector {
                 display: flex;
                 flex-direction: column;
@@ -948,6 +1056,8 @@ export class ExploreAlbumDetails extends LitElement implements ContextMenuHost {
         this.releases = [];
         this.versionEntries = [];
         this.selectedVersionKey = '';
+        this.defaultVersionKey = '';
+        this.versionsOpen = false;
         this.showFullTracklist = null;
         this.localTracks = [];
         this.filePaths = new Map();
@@ -1639,6 +1749,14 @@ export class ExploreAlbumDetails extends LitElement implements ContextMenuHost {
             || standardEntry?.key
             || this.versionEntries[0]?.key
             || '';
+
+        // Recorded here rather than derived later: this is the one
+        // place that knows what "the version we picked" means, and
+        // recomputing the preference order at the render site would be
+        // a second copy of it.  `handleTracklistScopeChange` rebuilds
+        // through here too, so the switch does not read as a choice of
+        // version.
+        this.defaultVersionKey = this.selectedVersionKey;
     }
 
     /**
@@ -2297,9 +2415,10 @@ export class ExploreAlbumDetails extends LitElement implements ContextMenuHost {
                     entity-type="album"
                     @catalog-retry=${this.retryCatalog}
                 ></catalog-scope-notice>
-                ${this.renderVersionSelector()}
+                ${this.renderChosenVersion()}
                 ${this.renderTracklistScope()}
                 ${this.renderTracklist()}
+                ${this.renderVersionSelector()}
             </div>
             <track-details></track-details>
         `;
@@ -2950,26 +3069,81 @@ export class ExploreAlbumDetails extends LitElement implements ContextMenuHost {
 
     /* ── Version Selector (R025, R026, R027) ── */
 
+    /**
+     * Which pressing is on screen — said only when the user chose it.
+     *
+     * The selector is a disclosure below the tracklist now, so nothing
+     * above the list names the version it came from. That is right for
+     * the default, which is what the header already describes; it is
+     * wrong the moment someone picks a different one, because then the
+     * tracklist and the page disagree and the control that explains it
+     * is off the bottom of the screen.
+     *
+     * `defaultVersionKey` is the whole test. A quiet line that appears
+     * on every album would be the thing this issue removed, one size
+     * smaller.
+     */
+    private renderChosenVersion() {
+        if (this.loadingReleases || this.errorReleases) return nothing;
+        if (!this.selectedVersionKey) return nothing;
+        if (this.selectedVersionKey === this.defaultVersionKey) return nothing;
+
+        const current = this.currentVersion();
+
+        if (!current) return nothing;
+
+        return html`
+            <p class="chosen-version">
+                Showing <strong>${current.label}</strong> —
+                ${current.sublabel}.
+                <button
+                    type="button"
+                    class="chosen-version-reset"
+                    @click=${this.resetVersion}
+                >
+                    Use the default version
+                </button>
+            </p>
+        `;
+    }
+
+    /** Back to what `buildClusters` picked, without opening the panel. */
+    private resetVersion = () => {
+        if (!this.defaultVersionKey) return;
+
+        this.selectedVersionKey = this.defaultVersionKey;
+    };
+
+    /**
+     * "Other versions" — a disclosure, below the tracklist.
+     *
+     * Choosing which pressing you are looking at is an advanced,
+     * metadata-repair task, and it used to sit directly above the
+     * tracklist with a heading and a paragraph of prose explaining our
+     * clustering heuristic. It is not removed — matching the wrong
+     * release is a real problem and this is how it gets fixed — it is
+     * demoted (#17).
+     *
+     * Two things about the shape are load-bearing, and both are
+     * `config-section`'s rules rather than new ones. The header is a
+     * real `<button aria-expanded aria-controls>` inside the heading
+     * that names the section, so it is reachable by Tab and by heading
+     * navigation alike. And the body **renders unconditionally and is
+     * toggled with `hidden`**, because `aria-controls` has to name an
+     * element that is in the DOM.
+     *
+     * The loading and error states this used to own are gone rather
+     * than moved. Both were unguarded, so they took the primary slot on
+     * every album regardless of whether there was ever going to be a
+     * choice: the spinner said the same thing `renderTracklist` was
+     * already saying about the same fetch, and the error is the one
+     * `catalog-scope-notice` shows at the top of the page with a retry
+     * — every path that sets `errorReleases` also sets `catalogFailed`,
+     * which is the only route to `unavailable`. What the tracklist does
+     * with a failure is now the tracklist's own business.
+     */
     private renderVersionSelector() {
-        if (this.loadingReleases) {
-            return html`
-                <section>
-                    <h3 class="section-header">Versions</h3>
-                    <div class="section-loading">Loading releases\u2026</div>
-                </section>
-            `;
-        }
-        if (this.errorReleases) {
-            return html`
-                <section>
-                    <h3 class="section-header">Versions</h3>
-                    <div class="section-error">
-                        <wa-icon name="triangle-exclamation"></wa-icon>
-                        ${this.errorReleases}
-                    </div>
-                </section>
-            `;
-        }
+        if (this.loadingReleases || this.errorReleases) return nothing;
 
         // A dropdown is only a choice if the choices differ. Counting
         // *entries* is the wrong test: a release group routinely has
@@ -2980,7 +3154,9 @@ export class ExploreAlbumDetails extends LitElement implements ContextMenuHost {
         //
         // Distinct *tracklists* is the real question, and it is already
         // computed: clusters are keyed by tracklist fingerprint.
-        if (this.distinctTracklistCount() <= 1) return nothing;
+        const choices = this.distinctTracklistCount();
+
+        if (choices <= 1) return nothing;
 
         const aggregateEntries = this.versionEntries.filter(
             (e) => e.group === 'aggregate',
@@ -2990,35 +3166,59 @@ export class ExploreAlbumDetails extends LitElement implements ContextMenuHost {
         );
 
         return html`
-            <div class="version-selector">
-                <div class="version-selector-row">
-                    <label for="version-select">Version</label>
-                    <select
-                        id="version-select"
-                        @change=${this.handleVersionChange}
-                        aria-label="Select release version"
+            <section class="versions">
+                <h3 class="versions-heading">
+                    <button
+                        type="button"
+                        class="versions-toggle"
+                        aria-expanded=${this.versionsOpen ? 'true' : 'false'}
+                        aria-controls="versions-body"
+                        @click=${this.toggleVersions}
                     >
-                        ${aggregateEntries.length > 0
-                            ? html`
-                                  <optgroup label="Aggregate">
-                                      ${aggregateEntries.map((e) =>
-                                          this.renderVersionOption(e),
-                                      )}
-                                  </optgroup>
-                              `
-                            : nothing}
-                        <optgroup label="Versions">
-                            ${clusterEntries.map((e) =>
-                                this.renderVersionOption(e),
-                            )}
-                        </optgroup>
-                    </select>
+                        <wa-icon name="chevron-down" aria-hidden="true"></wa-icon>
+                        Other versions of this album (${choices})
+                    </button>
+                </h3>
+                <div id="versions-body" ?hidden=${!this.versionsOpen}>
+                    <p class="versions-intro">
+                        A release group can have several pressings with
+                        different tracklists. Pick another if the one
+                        above does not match your copy.
+                    </p>
+                    <div class="version-selector">
+                        <div class="version-selector-row">
+                            <label for="version-select">Version</label>
+                            <select
+                                id="version-select"
+                                @change=${this.handleVersionChange}
+                            >
+                                ${aggregateEntries.length > 0
+                                    ? html`
+                                          <optgroup label="Aggregate">
+                                              ${aggregateEntries.map((e) =>
+                                                  this.renderVersionOption(e),
+                                              )}
+                                          </optgroup>
+                                      `
+                                    : nothing}
+                                <optgroup label="Versions">
+                                    ${clusterEntries.map((e) =>
+                                        this.renderVersionOption(e),
+                                    )}
+                                </optgroup>
+                            </select>
+                        </div>
+                        ${this.renderVersionMeta()}
+                    </div>
                 </div>
-                ${this.renderVersionMeta()}
-            </div>
+            </section>
         `;
     }
 
+    private toggleVersions = () => {
+        this.versionsOpen = !this.versionsOpen;
+    };
+
     /**
      * One option in the version list.
      *
@@ -3197,8 +3397,21 @@ export class ExploreAlbumDetails extends LitElement implements ContextMenuHost {
             `;
         }
         if (this.errorReleases) {
-            // Error already shown in version selector section
-            return nothing;
+            // The failure belongs to the list that is missing because
+            // of it. This used to return `nothing` and lean on the
+            // version selector's own error block to have said it, which
+            // is precisely the coupling that made demoting the selector
+            // a rewrite rather than a move: a control in a collapsed
+            // disclosure cannot be the page's error surface.
+            return html`
+                <section>
+                    <h3 class="sr-only">Tracklist</h3>
+                    <div class="section-error">
+                        <wa-icon name="triangle-exclamation"></wa-icon>
+                        ${this.errorReleases}
+                    </div>
+                </section>
+            `;
         }
         const current = this.currentVersion();
         if (!current) {

frontend/test/components/album-version-demotion.test.ts

@@ -0,0 +1,278 @@
+/**
+ * Choosing a pressing is a repair job, not the album page's headline.
+ *
+ * The version selector sat directly above the tracklist with a heading,
+ * a `<select>` and a paragraph explaining how our clustering picks a
+ * "standard version" — the most valuable space on the page spent on a
+ * control a normal user never touches (#17). Two more blocks shared
+ * that slot and were not even guarded by "is there a choice": a
+ * `Versions / Loading releases…` spinner about the same fetch
+ * `renderTracklist` was already reporting, and a `Versions / <error>`
+ * block duplicating what `catalog-scope-notice` shows at the top of the
+ * page with a retry.
+ *
+ * What is pinned here is the demotion and the three things that must
+ * survive it: the control is still reachable, the page still says which
+ * version you are looking at once you have chosen one, and a failed
+ * fetch still says so somewhere a collapsed panel is not.
+ */
+import { describe, expect, it, beforeEach } from 'vitest';
+import type { LitElement } from 'lit';
+import { page } from 'vitest/browser';
+
+import '@components/explore-album-details/explore-album-details';
+import { stub, stubFailure, flush, resetHarness } from '@test/support/harness';
+import { fixture, shadow, shadowAll } from '@test/support/render';
+
+const MBID = 'rg-0001';
+
+function track(n: number) {
+  return {
+    position: n,
+    discNumber: 1,
+    title: `Track ${n}`,
+    length: 200000,
+    mbid: `rec-${n}`,
+    inLibrary: false,
+  };
+}
+
+function release(mbid: string, date: string, trackCount: number) {
+  return {
+    mbid,
+    title: 'Glass Harbour',
+    date,
+    status: 'Official',
+    tracks: Array.from({ length: trackCount }, (_, i) => track(i + 1)),
+  };
+}
+
+const UNKNOWN = { owned: 0, expected: 0, known: false, complete: false };
+
+/** Two releases whose tracklists genuinely differ, so there is a choice. */
+const TWO = [release('rel-1', '2019-04-01', 10), release('rel-2', '2020-09-01', 14)];
+
+async function album(releases: unknown[] = TWO): Promise<LitElement> {
+  stub('explore.Service.BrowseReleases', releases);
+  stub('library.Library.GetAlbumCompleteness', UNKNOWN);
+  stub('library.Library.GetAlbumTracks', []);
+
+  const el = await fixture<LitElement>('explore-album-details', {
+    releaseGroupMBID: MBID,
+    localAlbumId: 7,
+    albumName: 'Glass Harbour',
+  });
+
+  await flush();
+  await el.updateComplete;
+
+  return el;
+}
+
+/** Positions of two selectors within the shadow root, in document order. */
+function order(el: Element, first: string, second: string): [number, number] {
+  const all = [...(el.shadowRoot?.querySelectorAll('*') ?? [])];
+  const a = all.findIndex((n) => n.matches(first));
+  const b = all.findIndex((n) => n.matches(second));
+
+  return [a, b];
+}
+
+beforeEach(() => {
+  resetHarness();
+  stub('explore.Service.LookupReleaseGroup', {
+    mbid: MBID,
+    title: 'Glass Harbour',
+    artistCredit: 'Tideline',
+  });
+  stub('explore.Service.GetThumbnail', '');
+  stub('library.Library.GetAllLibrariesWithTrackCounts', []);
+  stub('library.Library.GetFilePathsByRecordingMBIDs', {});
+});
+
+describe('the version selector is no longer the headline', () => {
+  it('renders after the tracklist, not before it', async () => {
+    const el = await album();
+    const [tracklist, versions] = order(el, '.tracklist', '.versions');
+
+    expect(tracklist).toBeGreaterThan(-1);
+    expect(versions).toBeGreaterThan(tracklist);
+  });
+
+  it('starts collapsed', async () => {
+    const el = await album();
+
+    expect(shadow(el, '#versions-body')?.hasAttribute('hidden')).toBe(true);
+  });
+
+  /**
+   * `aria-controls` has to name an element that is in the DOM, so the
+   * body renders unconditionally and is toggled with `hidden` — the
+   * rule `config-section` states and the reason a conditional body
+   * would be wrong here too.
+   */
+  it('keeps the panel in the DOM while it is shut', async () => {
+    const el = await album();
+
+    expect(shadow(el, '#versions-body')).not.toBeNull();
+    expect(
+      shadow(el, '.versions-toggle')?.getAttribute('aria-controls'),
+    ).toBe('versions-body');
+  });
+
+  /**
+   * The browser's own answer: a disclosure that cannot be tabbed to is
+   * the fault `config-section` shipped for every setting in the app,
+   * and a shadow-root query cannot tell you a control has a name.
+   */
+  it('is a named, expandable button', async () => {
+    await album();
+
+    await expect
+      .element(
+        page.getByRole('button', { name: /Other versions of this album \(2\)/ }),
+      )
+      .toBeInTheDocument();
+  });
+
+  it('opens when the button is pressed', async () => {
+    const el = await album();
+    const toggle = shadow<HTMLButtonElement>(el, '.versions-toggle');
+
+    expect(toggle?.getAttribute('aria-expanded')).toBe('false');
+
+    toggle?.click();
+    await el.updateComplete;
+
+    expect(toggle?.getAttribute('aria-expanded')).toBe('true');
+    expect(shadow(el, '#versions-body')?.hasAttribute('hidden')).toBe(false);
+  });
+
+  it('says nothing at all when there is only one tracklist', async () => {
+    const el = await album([release('rel-1', '2019-04-01', 10)]);
+
+    expect(shadow(el, '.versions')).toBeNull();
+  });
+});
+
+describe('the two blocks that shared that slot', () => {
+  /**
+   * The spinner was unguarded, so `Versions / Loading releases…` took
+   * the primary position on *every* album load — including the ones
+   * that would never offer a choice — beside `renderTracklist`'s own
+   * "Loading tracks…" about the same fetch.
+   */
+  it('no longer reports the same fetch twice while loading', async () => {
+    stub('library.Library.GetAlbumCompleteness', UNKNOWN);
+    stub('library.Library.GetAlbumTracks', []);
+    stub('explore.Service.BrowseReleases', () => new Promise(() => {}));
+
+    const el = await fixture<LitElement>('explore-album-details', {
+      releaseGroupMBID: MBID,
+      albumName: 'Glass Harbour',
+    });
+
+    const loading = shadowAll(el, '.section-loading');
+
+    expect(loading).toHaveLength(1);
+    expect(loading[0]?.textContent).toContain('Loading tracks');
+  });
+
+  /**
+   * A failed browse must still be visible, and it cannot be visible
+   * from inside a collapsed disclosure. It belongs to the list that is
+   * missing because of it — `renderTracklist` used to return `nothing`
+   * here and lean on the selector's own error block, which is exactly
+   * the coupling that made this a rewrite rather than a move.
+   */
+  it('reports a failed fetch in the tracklist, once', async () => {
+    stub('library.Library.GetAlbumCompleteness', UNKNOWN);
+    stub('library.Library.GetAlbumTracks', []);
+    stubFailure('explore.Service.BrowseReleases', 'the catalog said no');
+
+    const el = await fixture<LitElement>('explore-album-details', {
+      releaseGroupMBID: MBID,
+      albumName: 'Glass Harbour',
+    });
+
+    await flush();
+    await el.updateComplete;
+
+    const errors = shadowAll(el, '.section-error');
+
+    expect(errors).toHaveLength(1);
+    expect(errors[0]?.textContent).toContain('versions');
+    expect(shadow(el, '.versions')).toBeNull();
+  });
+});
+
+describe('which version is on screen', () => {
+  /**
+   * The default is what the header already describes, so a line saying
+   * so on every album would be the thing this issue removed, one size
+   * smaller.
+   */
+  it('is not stated while the page picked it', async () => {
+    const el = await album();
+
+    expect(shadow(el, '.chosen-version')).toBeNull();
+  });
+
+  /**
+   * The moment someone chooses another, the tracklist and the header
+   * disagree — and the control that explains it is now off the bottom
+   * of the page.
+   */
+  it('is stated above the tracklist once the user chooses', async () => {
+    const el = await album();
+    const select = shadow<HTMLSelectElement>(el, '#version-select')!;
+    const other = [...select.options].find((o) => o.value !== select.value)!;
+
+    select.value = other.value;
+    select.dispatchEvent(new Event('change'));
+    await el.updateComplete;
+
+    const line = shadow(el, '.chosen-version');
+
+    expect(line).not.toBeNull();
+
+    const [chosen, tracklist] = order(el, '.chosen-version', '.tracklist');
+
+    expect(chosen).toBeGreaterThan(-1);
+    expect(tracklist).toBeGreaterThan(chosen);
+  });
+
+  it('offers a way back, which clears the line', async () => {
+    const el = await album();
+    const select = shadow<HTMLSelectElement>(el, '#version-select')!;
+    const first = select.value;
+    const other = [...select.options].find((o) => o.value !== first)!;
+
+    select.value = other.value;
+    select.dispatchEvent(new Event('change'));
+    await el.updateComplete;
+
+    shadow<HTMLButtonElement>(el, '.chosen-version-reset')?.click();
+    await el.updateComplete;
+
+    expect(shadow<HTMLSelectElement>(el, '#version-select')?.value).toBe(first);
+    expect(shadow(el, '.chosen-version')).toBeNull();
+  });
+
+  /** A panel that shuts on use cannot be used twice. */
+  it('leaves the disclosure open after a choice', async () => {
+    const el = await album();
+
+    shadow<HTMLButtonElement>(el, '.versions-toggle')?.click();
+    await el.updateComplete;
+
+    const select = shadow<HTMLSelectElement>(el, '#version-select')!;
+    const other = [...select.options].find((o) => o.value !== select.value)!;
+
+    select.value = other.value;
+    select.dispatchEvent(new Event('change'));
+    await el.updateComplete;
+
+    expect(shadow(el, '#versions-body')?.hasAttribute('hidden')).toBe(false);
+  });
+});