- MnemonicBuilder: 12 NOVICE_LETTERS, real-time validatePhrase, save/skip
- OnboardingPage: wraps builder, passes token and onComplete
- App.tsx: post-auth fetch /api/mnemonics, route to onboarding if <12 saved
- Fix: validatePhrase called with letter (not Morse pattern) as second arg
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
