fix to artist unwatch/watch bug

src/routes/artists.rs

@@ -349,6 +349,11 @@ pub async fn enrich_artist(
         }
     };
 
+    // Backfill artist MBID if the DB record doesn't have one yet (e.g., from import)
+    if artist.musicbrainz_id.is_none() && id.is_some() {
+        let _ = queries::artists::upsert(state.db.conn(), &artist.name, Some(&mbid)).await;
+    }
+
     // Fetch artist photo + bio + banner (cached, provider-aware)
     let config = state.config.read().await;
     let image_source = config.metadata.artist_image_source.clone();