[FEATURE] Newsletter/email subscription system #44
Description
Allow parents to subscribe to a newsletter. Options: age-based subscriptions (content relevant to their child's age), domain-based notifications (new articles in domains they follow), or weekly digest.
Backend: FastAPI on Mac Mini with Cloudflare Tunnel. Email delivery: Resend or SendGrid free tier. Store subscriber data in PostgreSQL. GDPR/privacy compliant — easy unsubscribe.
Milestone: 5 - Site Features v2