v17.5.23 — Developer MFA + SaaS registration

- Developer MFA recovers stale unverified TOTP and confirms AAL2.
- Login/Register tabs added.
- Registration asks for company name, email and password confirmation.
- New company is created automatically after confirmation/login.
- Server grants Full trial for 14 days.
- Starter catalog contains the current 113 positions; orders and clients start empty.
- PWA cache bumped to v57.