List Lucid (Lucidchart/Lucidspark) billing invoices, returning total plus each invoice's date, number, description and amount — metadata only. Feed a row's number to lucid.app/download_invoice to fetch that invoice's PDF. Works whatever language the account is set to. An account with no invoices returns an empty list, and a billing page that never finishes loading is reported as an error rather than passed off as an empty one.