It is the first time OpenAI has backed a specific federal mandate requiring third-party safety assessors to review the work of the top companies developing advanced AI.But the company — whose lobbyists hold tremendous sway on Capitol Hill and across statehouses — has tiptoed closer to the idea for days.Last week, OpenAI belatedly endorsed a California bill establishing an accreditation and vetting process for “independent verification organizations,” a technical term encompassing a stable of mos...