fix(web): resolve album names to the studio Album, not a same-title Single

searchReleaseGroup took the first MusicBrainz hit, so a title MB ranks with the
single first (e.g. "Thriller" ties single+album at score 100) resolved to the
single — the Last.fm album modal and the Want flow then showed a 1-track single.
Prefer a clean Album > EP > Single > album-with-secondary, keeping MB order as the
in-tier tiebreak; single-only titles still resolve.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/lib/musicbrainz.test.ts

@@ -48,6 +48,26 @@ describe("musicbrainz module", () => {
     expect(await searchReleaseGroup("Nobody", "Nothing")).toBeNull();
   });
 
+  it("prefers a clean studio Album over a same-title Single/comp that MB ranks first", async () => {
+    // MB ties the "Thriller" single with the album at the same score and lists the single
+    // first; we must resolve to the studio album, not the single.
+    vi.stubGlobal("fetch", vi.fn(() => jsonResponse({ "release-groups": [
+      { id: "single", title: "Thriller", "primary-type": "Single", "secondary-types": [], "first-release-date": "1983", "artist-credit": [{ artist: { id: "mj", name: "Michael Jackson" } }] },
+      { id: "comp", title: "Thriller", "primary-type": "Album", "secondary-types": ["Compilation"], "first-release-date": "2015", "artist-credit": [{ artist: { id: "mj", name: "Michael Jackson" } }] },
+      { id: "album", title: "Thriller", "primary-type": "Album", "secondary-types": [], "first-release-date": "1982", "artist-credit": [{ artist: { id: "mj", name: "Michael Jackson" } }] },
+    ] })));
+    const m = await searchReleaseGroup("Michael Jackson", "Thriller");
+    expect(m?.rgMbid).toBe("album");
+    expect(m?.primaryType).toBe("Album");
+  });
+
+  it("falls back to a Single when no album-type release group matches", async () => {
+    vi.stubGlobal("fetch", vi.fn(() => jsonResponse({ "release-groups": [
+      { id: "single-only", title: "Standalone", "primary-type": "Single", "secondary-types": [], "first-release-date": "2020", "artist-credit": [{ artist: { id: "a1", name: "Artist" } }] },
+    ] })));
+    expect((await searchReleaseGroup("Artist", "Standalone"))?.rgMbid).toBe("single-only");
+  });
+
   it("escapes quotes in the release-group query", async () => {
     const fetchMock = vi.fn((_url: string, _init?: RequestInit) => jsonResponse({ "release-groups": [] }));
     vi.stubGlobal("fetch", fetchMock);

web/src/lib/musicbrainz.ts

@@ -58,12 +58,29 @@ function escapeLucenePhrase(s: string): string {
   return s.replace(/[\\"]/g, (c) => "\\" + c);
 }
 
+// When several release groups share the searched title (e.g. MusicBrainz ties the
+// "Thriller" single with the album at the same score, listing the single first), prefer
+// the canonical studio album. Lower rank = better; MB's own ordering breaks ties within
+// a tier. A title that only exists as a single still resolves (it's the best available).
+function albumPreferenceRank(g: any): number {
+  const primary = g["primary-type"] ?? "";
+  const hasSecondary = (g["secondary-types"] ?? []).length > 0;
+  if (primary === "Album" && !hasSecondary) return 0; // clean studio album
+  if (primary === "EP" && !hasSecondary) return 1;
+  if (primary === "Single" && !hasSecondary) return 2;
+  if (primary === "Album") return 3; // album with a secondary type (compilation, live, demo…)
+  return 4;
+}
+
 export async function searchReleaseGroup(artist: string, album: string): Promise<ReleaseGroupMatch | null> {
   const query = `releasegroup:"${escapeLucenePhrase(album)}" AND artist:"${escapeLucenePhrase(artist)}"`;
   const data = await mbGet(`/release-group?query=${encodeURIComponent(query)}&fmt=json&limit=5`);
   const groups: any[] = data["release-groups"] ?? [];
   if (groups.length === 0) return null;
-  const g = groups[0];
+  // groups arrive in MB relevance order; keep that as the tiebreak (reduce only switches on
+  // a strictly better rank, so equal-ranked earlier hits win).
+  const g = groups.reduce((best, cur) =>
+    albumPreferenceRank(cur) < albumPreferenceRank(best) ? cur : best);
   const credit = g["artist-credit"]?.[0]?.artist ?? {};
   return { ...toReleaseGroup(g), artistMbid: credit.id ?? "", artistName: credit.name ?? artist };
 }