Small filesystem and command helpers around HostKit runners.
@spec chmod(Path.t(), non_neg_integer() | nil, keyword()) :: :ok | {:error, term()}
@spec chown(Path.t(), String.t() | nil, String.t() | nil, keyword()) :: :ok | {:error, term()}
@spec cmd(keyword(), String.t(), [String.t()], keyword()) :: :ok | {:error, term()}
@spec runner(keyword()) :: module() | {module(), keyword()}