A proper welcome mail, and a passkey
The mail that confirms your address now looks like Tinderbox Works instead of a plain block of text. And a new account is offered a passkey right after naming its studio: from then on you sign in with your fingerprint, face or screen lock. Not now skips it.
New
A passkey for new accounts.
Right after a new account names its studio (or joins one from an invite), Add a passkey comes up once. A passkey signs you in with your fingerprint, face or screen lock: no password and no one-time code, and it only works on Tinderbox Works, so it can't be phished. Not now skips it; you can add one later from Settings. If the passkey dialog is closed or times out, you can try again or still skip.
Changed
The confirmation mail, in our look.
Confirm your email now arrives as a Tinderbox Works mail: the mark, a short welcome, one Confirm my email button, how long it works and a plain link for when the button doesn't. Built with tables and inline colours, the way mail clients like it, with a plain-text version beside it. Other mails from sign-in (reset password) get the same frame.