BCC registration confirmations to contact@cryptocommonsgather.ing

Organizers now receive a copy of every successful payment confirmation
email so they're notified of new registrations.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/email.ts

@@ -92,6 +92,7 @@ export async function sendPaymentConfirmation(
     const info = await transport.sendMail({
       from: EMAIL_FROM,
       to: data.email,
+      bcc: "contact@cryptocommonsgather.ing",
       subject: "Registration Confirmed - Crypto Commons Gathering 2026",
       html,
     })