Initial commit: Mail service with Brevo SMTP

- Express server with REST API for sending emails
- SQLite database for persistent email history
- Web interface with form (recipient, CC, subject, text/HTML)
- Email footer with embedded image (CID attachment)
- Nodemailer configured for Brevo SMTP relay

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,3 @@
+node_modules/
+.env
+data/*.db