@type class() ::
  :validation
  | :forbidden
  | :approval_required
  | :not_found
  | :timeout
  | :cancelled
  | :transient_transport
  | :resource_conflict
  | :execution_failure
  | :malformed_result
  | :budget_exceeded
  | :unsupported_capability
  | :unknown_outcome
  | :overloaded

@type t() :: %Backplane.AgentRuntime.Error{
  cause: term() | nil,
  class: class(),
  details: map(),
  message: String.t() | nil
}