feat: enable email notifications in Coolify

- Add MAIL_MAILER=smtp to use SMTP transport
- Configure MAIL_HOST and MAIL_PORT to use Mailpit relay
- Set MAIL_FROM_ADDRESS and MAIL_FROM_NAME for sender info
- No encryption/auth needed for internal Mailpit relay

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

dev/compose.yaml

@@ -126,6 +126,15 @@ services:
       - PUSHER_APP_SECRET=${DEV_COOLIFY_PUSHER_APP_SECRET}
       - PUSHER_SCHEME=https
       - SSL_MODE=off
+      # Mail configuration
+      - MAIL_MAILER=smtp
+      - MAIL_HOST=net_mailpit
+      - MAIL_PORT=1025
+      - MAIL_ENCRYPTION=
+      - MAIL_USERNAME=
+      - MAIL_PASSWORD=
+      - MAIL_FROM_ADDRESS=${EMAIL_FROM}
+      - MAIL_FROM_NAME=Coolify
     networks:
       - compose_network
     labels: