feat: Arrow annotations #40
Description
Summary
Add arrow annotations to point to specific code sections.
Motivation
Visual emphasis helps explain what's wrong/right.
Implementation
- Drawing mode for arrows
- Arrow customization (color, style)
- Arrows persist with comparison
- Export includes annotations
Acceptance Criteria
- Draw arrows on code panels
- Customize arrow appearance
- Arrows visible in export
- Delete/edit arrows
Story Points
5 points