Add SearchArtists and GetArtistAlbums proxy RPCs to music-agregator service

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/claude-agent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

internal/metadata/service.go

@@ -54,6 +54,30 @@ func (s *MetadataService) GetArtistAlbums(ctx context.Context, artistExternalID
 	return resp.GetAlbums(), nil
 }
 
+func (s *MetadataService) SearchArtists(ctx context.Context, query string, limit, offset int32) (*metadataPb.SearchArtistsResponse, error) {
+	resp, err := s.client.SearchArtists(ctx, &metadataPb.SearchArtistsRequest{
+		Query:  query,
+		Limit:  limit,
+		Offset: offset,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("searching artists: %w", err)
+	}
+	return resp, nil
+}
+
+func (s *MetadataService) GetArtistAlbumsWithPagination(ctx context.Context, artistID string, limit, offset int32) (*metadataPb.GetArtistAlbumsResponse, error) {
+	resp, err := s.client.GetArtistAlbums(ctx, &metadataPb.GetArtistAlbumsRequest{
+		ArtistId: artistID,
+		Limit:    limit,
+		Offset:   offset,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("fetching artist albums: %w", err)
+	}
+	return resp, nil
+}
+
 func (s *MetadataService) GetAlbumTracks(ctx context.Context, albumExternalID string) ([]*metadataPb.Track, error) {
 	resp, err := s.client.GetAlbumTracks(ctx, &metadataPb.GetAlbumTracksRequest{
 		AlbumId: albumExternalID,