IDs got rounded on their way through JSON

Order numbers from a new system are 17 digits. They came out of JSON.parse in the browser off by a few, so the "order not found" pages were getting ...993 turned into ...992. Number.MAX_SAFE_INTEGER is 9007199254740991, past that doubles can't represent every integer. Send IDs as strings. "Identifiers aren't numbers" as somebody said here.