1. Auto dark mode: detect system prefers-color-scheme, auto-switch industrial/modern theme
2. Email quotation endpoint: POST /quotations/:id/email sends HTML email via SMTP
3. Camera barcode scanner: BarcodeDetector API with getUserMedia overlay in catalog
4. Returns with warranty: POST /returns endpoint with stock restoration and sale status tracking
5. Partial offline catalog: cache top 500 parts in IndexedDB, search when offline
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>