Add Email Notifications to Lovable App

Add email notifications to my Lovable app using Resend.

REQUIREMENTS:
1. Create a Supabase Edge Function "send-email" that accepts: to, subject, template name, and template variables.
2. Build HTML email templates using React Email components for: Welcome Email (sent on signup), Form Submission Alert (sent to admin when a form is submitted), and Status Update (sent to users when their request status changes).
3. Trigger welcome email automatically when a new user signs up using a Supabase database webhook on the auth.users table.
4. Trigger form alert email when a new row is inserted into any contact/inquiry table.
5. Add an email preferences page where users can opt in/out of different notification types. Store preferences in a "notification_preferences" table.
6. Include unsubscribe link in every email that updates preferences.
7. Log all sent emails in a "email_logs" table for debugging.

DATABASE:
- "notification_preferences" table: id, user_id, welcome_emails, form_alerts, marketing, created_at
- "email_logs" table: id, to_email, template, subject, status, error, sent_at

ENVIRONMENT VARIABLES:
- RESEND_API_KEY
- FROM_EMAIL (e.g., notifications@yourdomain.com)

SECURITY:
- Rate limit email sending to prevent abuse.
- Validate email addresses before sending.
- Never include sensitive data in email content.