Ask HN: Software that autonomously updates your account details on every site?

I'm looking to update hundreds of online accounts to use my new email domain. With the LLM craze over the past few years, is there an open source project that could semi-autonomously update the details for all of them?

Ideally it would hook into my password database, email accounts, and just have me confirm actions, enter SMS 2FA codes or tap my yubikey when required. It seems like a generally solvable problem now that LLMs exist.