onboarding new users
@Better Auth I'm using social logins/sign ups (google and github) and passwordless otp for email signups in my next js app. if a user sign ups using google / github we can assume email is verified. And if new user successfully verifies otp token during sign in, we create session and redirect to onboarding route. how do i differentiate new users from old users during sign in. what is the auth configuration to achieve this?