- Add POST /user/email/code endpoint to send 6-digit verification code
- Require email code verification before completing registration
- Add email code cache with 10min TTL and 5/day send rate limit
- Fix nil client guard, TLS conn leak, domain parsing, and Resend error body in email pkg
- Deploy via ssh inline command using current branch
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>