- Created SpanRectanglePrimitive.ts implementing ISeriesPrimitive interface
- Implemented updateAllViews() with coordinate conversion from data-space to pixel-space
- Added semi-transparent rectangle rendering with configurable opacity
- Implemented label tag rendering above rectangles showing pattern names
- Added hitTest() for click detection within span bounds
- Implemented highlight state with thicker borders and increased opacity
- Set zOrder to 'bottom' to render rectangles behind candlesticks
- Completed Section 4 tasks (4.1-4.6) from span-annotation specification
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
