update

src/library/track.rs

@@ -107,6 +107,7 @@ impl ToAPI for Track {
         json!({
             "id": self._id,
             "title": self.title,
+            "track_number": self.meta.as_ref().map(|x| x.track_number()),
             "meta": serde_json::to_value(&self.meta).unwrap(),
             "album_id": self.album_id.as_ref().map(|x| x.id().to_string()),
             "album": album_title,