@type t() :: %PromptRunner.Source.Result{
  commit_messages: %{optional({String.t(), String.t() | nil}) => String.t()},
  legacy_config: PromptRunner.Config.t() | nil,
  metadata: map(),
  phase_names: map(),
  project_dir: String.t() | nil,
  prompts: [PromptRunner.Prompt.t()],
  repo_groups: map(),
  source_root: String.t() | nil,
  target_repos: [map()] | nil
}