- Add 15+ styled email templates matching existing invite email design
- Wire up notification triggers in all routers (assignment, round, project, mentor, application, onboarding)
- Add test email button for each notification type in admin settings
- Add round-attached notifications: admins can configure which notification to send when projects enter a round
- Fall back to status-based notifications when round has no configured notification
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>