defmodule Cairnloop.Repo.Migrations.AddConversationIdToToolProposals do
  use Ecto.Migration

  def change do
    alter table(:cairnloop_tool_proposals) do
      add(:conversation_id, references(:cairnloop_conversations, on_delete: :nilify_all), null: true)
    end

    # Composite index for efficient conversation-scoped timeline queries (D-06)
    create(index(:cairnloop_tool_proposals, [:conversation_id, :inserted_at]))
  end
end