Plan 里的单个步骤。
Summary
Types
@type status() :: :pending | :in_progress | :completed | :failed | :skipped
@type t() :: %CMDC.Plan.Step{ completed_at: DateTime.t() | nil, description: String.t(), error: String.t() | nil, id: String.t(), notes: String.t() | nil, result: any() | nil, started_at: DateTime.t() | nil, status: status() }