@type t() :: %CouncilEx.Response{
  content: String.t(),
  latency_ms: non_neg_integer() | nil,
  model: String.t(),
  parsed: map() | nil,
  raw: term() | nil,
  usage: usage()
}

@type usage() :: %{input_tokens: non_neg_integer(), output_tokens: non_neg_integer()}