## Summary
- gate waitlist signup behind email confirmation so only verified leads
receive a queue position and referral code
- add signed lead verification routes, a check-email page, and a
dedicated verification email for the waitlist flow
- update lead syncing and feature tests so only verified leads are
exported to Resend and referral movement happens after verification
## Testing
- php artisan test --compact tests/Feature/UserLeadTest.php
- php artisan test --compact
tests/Feature/ResendSyncLeadsCommandTest.php
- php artisan test --compact tests/Feature/MailSenderTest.php
- vendor/bin/pint --dirty --format agent
d0aab3d11b