EXP: enrich artist info data via Last.fm and produce better embeddings

priv/repo/migrations/20260228225023_add_lastfm_data_to_artist_infos.exs

@@ -0,0 +1,9 @@
+defmodule MusicLibrary.Repo.Migrations.AddLastfmDataToArtistInfos do
+  use Ecto.Migration
+
+  def change do
+    alter table(:artist_infos) do
+      add :lastfm_data, :map, default: %{}
+    end
+  end
+end