v1.4 Live Activity Sync

Delivered: Real-time Claude Code operation visualization with highly visible flash animations

Key accomplishments:
- Claude Code PostToolUse hooks emit file operation events
- Read operations trigger distinct blue flash (0x4488FF)
- Enhanced flash visibility (3.5x emissive, 1.8x scale pulse)
- Animation batching for 60fps during rapid operations (50+ files)
- Hook status notification and debug mode for troubleshooting

See .planning/MILESTONES.md for full details.