Add similar records

Initial stab by Claude

priv/repo/migrations/20251011192421_create_record_embeddings.exs

@@ -0,0 +1,17 @@
+defmodule MusicLibrary.Repo.Migrations.CreateRecordEmbeddings do
+  use Ecto.Migration
+
+  def change do
+    create table(:record_embeddings, primary_key: false) do
+      add :id, :binary_id, primary_key: true
+      add :record_id, references(:records, type: :binary_id, on_delete: :delete_all), null: false
+
+      add :embedding, :text, null: false
+      add :text_representation, :text, null: false
+
+      timestamps(type: :utc_datetime)
+    end
+
+    create unique_index(:record_embeddings, [:record_id])
+  end
+end