fix(onboarding): prefill verified email in a disabled field; bump SDK 0.2.4

- Onboarding reads the OAuth email (session-storage hint + live Supabase
  session via getUserEmail) so Continue is no longer disabled.
- Replace the empty 'Signed in as' banner with a disabled, prefilled
  email field (email is fixed — Google-verified).
- Stash the verified email at OAuth callback time for onboarding prefill.
- Bump @abe-kap/appshell-sdk to ^0.2.4 (getUserEmail via getSession).

.gitignore

@@ -41,3 +41,4 @@ yarn-error.log*
 next-env.d.ts
 
 .vercel
+.env*.local