@type t() :: %Codex.Events.CollabAgentSpawnEnd{
  call_id: String.t() | nil,
  model: String.t() | nil,
  new_agent_nickname: String.t() | nil,
  new_agent_role: String.t() | nil,
  new_thread_id: String.t() | nil,
  prompt: String.t() | nil,
  reasoning_effort: String.t() | atom() | nil,
  sender_thread_id: String.t() | nil,
  status: Codex.Protocol.CollabAgentState.t() | nil
}