- Add customer email field and PayPal payment reminder emails with order reference (HEL-YEAR-ID format)
- Display stock availability with color-coded badges (available/low/unavailable)
- Add sale/clearance flag with animated red badge overlay
- Implement automatic fallback placeholder for missing/broken product images
- Add email column to order management view
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
