feat(web): add relations to task detail, animated subtasks, and keyboard nav
- Redesign relations with command palette for linking tasks
- Add relation rows matching subtask style (status/assignee popovers, context menu)
- Add animated list transitions for subtasks with framer-motion
- Add keyboard navigation (arrow keys, Space to select, Enter to open, Escape)
- Add focused row indicator with ring style
- Make Properties and Labels headings more readable in sidebar
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>