- Add new module src/app/story_bible_editor.rs for dedicated Story Bible editing
- Add 'Edit -> Story Bible' menu option to open the editor
- Tree view (left 1/3) shows Story Bible directory structure with collapsible folders
- Editor (right 2/3) allows editing selected Story Bible items
- Auto-load first file on open, support Ctrl+S to save
- Rebuild Story Bible index after saving to pick up changes
- Update README.md with Story Bible Editor documentation
Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>