Update to artist credit handling

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(