Make it so users cannot simply copy paste the recovery phrase in Create New Account flow

[pmespresso]

Several other wallets do this to make absolute sure the user actually did make a copy of the phrase.

The ideal behavior would be:

• the rewrite recovery phrase screen input should override Command V behavior to pop up a warning message along the lines of "We have disabled Copy/Pasting for this step to be certain you made a copy of the recovery phrase. Please go back to the previous screen and make a copy if you haven't already."

Edit: - Check if process.env.NODE_ENV !== 'production' then just allow copy/paste since it'd be very annoying not to have that in development

[ltfschoen]

I'd like to still be able to copy/paste the recovery phrase in development

[pmespresso]

We can check for NODE_ENV and allow it if not in production?

[amaury1093]

Yes, good idea.

Several other wallets do this to make absolute sure the user actually did make a copy of the phrase.

Following #100, I'd actually go the way Signer, Status and Exodus do: we don't force the user to make a copy of the phrase, just put a warning "account not backed up" if it's not backed up yet. This issue is still valid though.

[Tbaut]

Should we close then? ~~I'll open several issues to break down #100 later on.~~ edit: just saw https://github.com/paritytech/fether/pull/400 addresses most of it, we can open another issue for what's left.