Remove the ability to sign up for an account / sign in

### Your use case

#### What would you like to do?

Remove the ability to sign up for an account / sign in

#### Why would you like to do it?

Because it's an unnecessary complication to the app: the only significant benefit of logging into an existing account is to sync your "recent calls" list across devices, but this doesn't work so well today anyways because clients will hide any "recent calls" for which they don't know the password. We're moving towards a world in which the SPA is only used for guest access, and only having passwordless users would just simplify things for us maintenance-wise.

#### How would you like to achieve it?

Get rid of the log in / sign up / log out buttons/screens/etc. and only have automatically created, passwordless users.

### Have you considered any alternatives?

_No response_

### Additional context

_No response_