- Add googleapis for Google Sheets integration
- Create /api/register endpoint to record registrations with "Pending" status
- Update webhook to mark registrations as "Paid" when payment completes
- Add lib/google-sheets.ts with addRegistration and updatePaymentStatus functions
- Update docker-compose.yml with Google Sheets env vars
- Add .env.example documenting required environment variables
Flow: Form submit → Sheet (Pending) → Payment → Webhook → Sheet (Paid)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
