- Daily cron (8:00 AM) checks created and received invoices
- Alerts 3 days before due date and on due date
- Summary email to INVOICE_ALERT_EMAIL with grouped tables
- Tracks sent alerts in invoice_alert_log to prevent duplicates
- node-cron scheduler runs inside the app process
- Favicon files copied from PHP project
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>