Add comprehensive library expansion with new components and demos

- Add new libraries: ui-accessibility, ui-animations, ui-backgrounds, ui-code-display, ui-data-utils, ui-font-manager, hcl-studio
- Add extensive layout components: gallery-grid, infinite-scroll-container, kanban-board, masonry, split-view, sticky-layout
- Add comprehensive demo components for all new features
- Update project configuration and dependencies
- Expand component exports and routing structure
- Add UI landing pages planning document

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

projects/ui-backgrounds/src/styles/index.scss

@@ -0,0 +1,9 @@
+// Main entry point for ui-backgrounds styles
+
+// Import base components
+@import 'mixins';
+@import 'animations';  
+@import 'base';
+
+// Export mixins for external use
+// Users can import this file to get access to all background mixins and styles