@type t() :: %Codex.Events.GuardianApprovalReviewCompleted{
  action: map() | String.t() | nil,
  decision_source: :agent | String.t() | nil,
  review: Codex.Events.GuardianApprovalReview.t(),
  review_id: String.t() | nil,
  target_item_id: String.t() | nil,
  thread_id: String.t(),
  turn_id: String.t()
}