UX: Add warning to "Create account"

We see endless threads here from this UX failure causing people to lose funds.

It's not them, it's MetaMask.

In the Bitcoin world people are used to the paradigm of a seed phrase being used to generate multiple addresses. With a total lack of any explaination Metamask leaves people with the impression they are generating a new address they will be able to recover. edit: They are!!

Later MetaMask bugs and they reinstall, only to discover they have ~~lost their funds~~ edit: to re-create a derived key.

* ~~"You have generated a new Private/Public Key pair. Please write down this Private Key for your records. Failure to do so MAY RESULT IN LOST FUNDS and is your sole responsibility!!"~~

The issue names the “Create account” flow but provides no file or test. Start by locating that entry point and reviewing how account creation, derived keys, and recovery are currently explained; confirm the intended warning wording with maintainers. Done means users can distinguish creating an additional key from creating a recoverable seed-based wallet.

Written by the indexing model from the issue text.