- Add RDPDFReaderAnnotationMenuAction and RDPDFReaderExistingHighlightMenuAction enums to PDF contracts
- Enable highlight overlay view to detect tap gestures and report tapped highlights
- Implement existing highlight menu in Demo page: copy text, add/edit annotation, delete annotation, delete underline
- Handle menu actions in PDFDemoReaderViewController to persist changes
- Ensure highlight tap detection doesn't interfere with text selection
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>