Add TipTap editor with frontmatter support and auto-save
- Install TipTap editor with markdown extensions (StarterKit, Typography, Link, CodeBlock)
- Create TipTapEditor component with custom styling matching design system
- Create MenuBar component with formatting controls
- Create FrontmatterEditor component for YAML metadata editing
- Create EditorContainer component managing editor state and auto-save
- Add file content API client and React Query hooks
- Implement debounced auto-save (2 second delay)
- Add unsaved changes warning before page unload
- Integrate editor into DashboardApp
- Convert HTML to markdown using turndown library