Auth types: updates to registration features

[jzbahrai]

Description

As a new user, I want to be able to sign up to Notify without adding in a phone number because my employer has switched away from giving employees work mobile phones and over to other methods like Teams phone numbers which cannot accept text messages.

Currently, SMS is required to sign-up. There are three flavours for registering an account:

1. Self sign up via /register
2. Sign up via a team invite (/register-from-invite)
3. Sign up via an organization invite (/register-from-org-invite)

Workflows

You can see the current and target workflows for this feature here.

Acceptance Criteria

• Design: Change the sign up page https://staging.notification.cdssandbox.xyz/register to indicate phone number is optional.
• Phone number is optional when signing up via /register
• Phone number is optional when signing up via an invite
• Admins are no longer able to invite a user from an organization (its on this page: /organisations/{org_id}/users)
• When phone number is provided when signing up via /register, it is verified via an SMS code
• When phone number is provided when signing up via an invite, it is verified via an SMS code
• Design: After I create my account, I want to be able to pick my 2FA type (security key, email, SMS)
• Dev: Implement the design from above.

QA Steps

• Tested in a realistic production scenario

[connorscarolyns]

Link to current state screenshots: https://www.figma.com/design/T6gN6GxBubbXvAHGtgUxHl/Security-features?node-id=1774-1382&t=gaUEgme2isvu5bs7-4