Replaces the mock verify step (which accepted any 6 digits) with a real SMS
OTP: addPhone() → Supabase/Twilio texts a code → verifyPhone() confirms it.
- Registration creates the auth account when leaving the Account step, so the
phone can be attached + verified against a live Supabase session; finish()
no longer double-registers.
- Onboarding gains a real phone-verify step (Profile → Verify → Address).
- Email is trusted without an OTP in both flows (Supabase auto-confirms on
signup; Google verifies for onboarding), matching project config.
- Bump @abe-kap/appshell-sdk to ^0.2.6.