berrypod/priv/repo/migrations/20260128235847_create_product_images.exs

defmodule Berrypod.Repo.Migrations.CreateProductImages do
  use Ecto.Migration

  def change do
    create table(:product_images, primary_key: false) do
      add :id, :binary_id, primary_key: true

      add :product_id, references(:products, type: :binary_id, on_delete: :delete_all),
        null: false

      add :src, :string, null: false
      add :position, :integer, default: 0, null: false
      add :alt, :string

      timestamps(type: :utc_datetime)
    end

    # Composite index covers queries on product_id alone (leftmost prefix)
    create index(:product_images, [:product_id, :position])
  end
end