Email sign-ups start in the Lobby, and other improvements

Fixes

• Renaming a screen to more than 255 characters under Screens > a screen > Settings now says “Screen name should be at most 255 characters long.” under the name field, instead of failing with a generic error.
• On API v4.1, saving a screen whose name or location is over 255 characters, or whose notes are over 65,536, returns an error that names the field and its limit, instead of a generic error.
• Creating an API token with a name you already use, under Settings > Security > API tokens, now shows “Token name already in use” under the name field and keeps the name you typed, instead of a toast and an empty field.

Improvements

• The “Connect screen” dialog accepts screen names up to 255 characters, up from 50.
• Signing up with an email address now works like signing up with Google: instead of getting a workspace created for you, you create your first one in the Lobby. Your free trial starts when you create that workspace, not when you sign up.