This commit finalizes the migration to Material Design 3 by:
- Removing all Radix UI dependencies and imports:
* Migrated Avatar component to use native HTML with custom fallback handling
* Replaced Collapsible with custom React hooks for expand/collapse state
* Implemented AlertDialog using React Context with native divs
* Built Sheet component with Portal-like behavior and native HTML
* Converted Toggle and ToggleGroup to use React state management
* Updated SidebarMenuButton to remove Radix Slot dependency
- Removed deprecated SCSS module files (7 files):
* button.module.scss, accordion.module.scss, checkbox.module.scss
* radio-group.module.scss, select.module.scss, switch.module.scss
* split-screen-editor.module.scss
- Replaced Tailwind utility classes with inline styles and M3 classes:
* Updated SplitScreenEditor to use M3 CSS variables and flexbox/grid
* Migrated sidebar components to use M3 button and spacing classes
* Removed Radix color imports from theme.scss
- All components now use M3 design tokens via CSS custom properties
- Maintained API compatibility with existing component usage patterns
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
