Update to artist credit handling

src/musicbrainz.rs

@@ -150,6 +150,7 @@ impl MetadataProvider for MusicBrainzClient {
         let r: MbRecordingDetail = self.get_json(&url).await?;
 
         let (artist_name, artist_mbid) = extract_artist_credit(&r.artist_credit);
+        let secondary_artists = extract_secondary_artists(&r.artist_credit);
         Ok(RecordingDetails {
             mbid: r.id,
             title: r.title,
@@ -173,6 +174,7 @@ impl MetadataProvider for MusicBrainzClient {
                 .into_iter()
                 .map(|g| g.name)
                 .collect(),
+            secondary_artists,
         })
     }
     async fn search_artist(
@@ -275,19 +277,13 @@ impl MetadataProvider for MusicBrainzClient {
     }
 }
 
+/// Extract the primary artist from MusicBrainz artist credits.
+/// Always returns the first/primary artist only — never concatenates
+/// collaborators or featured artists into compound names.
 fn extract_artist_credit(credits: &Option<Vec<MbArtistCredit>>) -> (String, Option<String>) {
     match credits {
         Some(credits) if !credits.is_empty() => {
-            let name: String = credits
-                .iter()
-                .map(|c| {
-                    let mut s = c.artist.name.clone();
-                    if let Some(ref join) = c.joinphrase {
-                        s.push_str(join);
-                    }
-                    s
-                })
-                .collect();
+            let name = credits[0].artist.name.clone();
             let mbid = Some(credits[0].artist.id.clone());
             (name, mbid)
         }
@@ -295,6 +291,30 @@ fn extract_artist_credit(credits: &Option<Vec<MbArtistCredit>>) -> (String, Opti
     }
 }
 
+/// Extract non-featuring secondary artists from MusicBrainz artist credits.
+/// Returns (name, mbid) pairs for collaborators that aren't "featuring" credits.
+fn extract_secondary_artists(credits: &Option<Vec<MbArtistCredit>>) -> Vec<(String, String)> {
+    let Some(credits) = credits else { return vec![] };
+    if credits.len() <= 1 {
+        return vec![];
+    }
+
+    // Walk credits after the first. Stop at any "feat"/"ft." joinphrase
+    // from the PREVIOUS credit (since joinphrase is on the credit BEFORE the next artist).
+    let mut result = Vec::new();
+    for i in 0..credits.len() - 1 {
+        let jp = credits[i].joinphrase.as_deref().unwrap_or("");
+        let lower = jp.to_lowercase();
+        if lower.contains("feat") || lower.contains("ft.") {
+            break;
+        }
+        // The next credit is a non-featuring collaborator
+        let next = &credits[i + 1];
+        result.push((next.artist.name.clone(), next.artist.id.clone()));
+    }
+    result
+}
+
 fn urlencoded(s: &str) -> String {
     s.replace(' ', "+")
         .replace('&', "%26")

src/provider.rs

@@ -45,6 +45,9 @@ pub struct RecordingDetails {
     pub releases: Vec<ReleaseRef>,
     pub duration_ms: Option<u64>,
     pub genres: Vec<String>,
+    /// Non-featuring collaborators beyond the primary artist.
+    #[serde(default)]
+    pub secondary_artists: Vec<(String, String)>,
 }
 
 /// An artist match from a search query.

src/tagger.rs

@@ -105,7 +105,7 @@ pub async fn tag_track(
         (details, best_release)
     };
 
-    // Upsert artist with MusicBrainz ID
+    // Upsert primary artist with MusicBrainz ID
     let artist_id = match &details.artist_mbid {
         Some(mbid) => {
             Some(queries::artists::upsert(conn, &details.artist, Some(mbid)).await?.id)
@@ -115,6 +115,13 @@ pub async fn tag_track(
         }
     };
 
+    // Upsert secondary collaborator artists so they exist as separate library entries
+    for (name, mbid) in &details.secondary_artists {
+        if let Err(e) = queries::artists::upsert(conn, name, Some(mbid)).await {
+            tracing::warn!(artist = %name, error = %e, "failed to upsert secondary artist");
+        }
+    }
+
     // Upsert album from best release
     let (album_id, album_name) = if let Some(ref release) = best_release {
         let album = queries::albums::upsert(

tests/integration.rs

@@ -53,6 +53,7 @@ impl MetadataProvider for MockProvider {
                 }],
                 duration_ms: Some(413_000),
                 genres: vec!["Progressive Rock".into()],
+                secondary_artists: vec![],
             })
         } else {
             Err(shanty_tag::TagError::Other("not found".into()))