Replace custom SVG icons and @mui/icons-material with lucide-react for consistent,
lightweight icon management across the application.
## Changes
- Add lucide-react package and remove @mui/icons-material
- Create theme-aware Icon wrapper component with color resolution
- Create iconMap.js for legacy icon name mappings
- Migrate 64 components to use new Icon component
- Remove 74 unused SVG files from assets/icons/
## Benefits
- Consistent icon API across the application
- Smaller bundle size with tree-shakeable imports
- Theme-aware color support via MUI theme paths
- Simpler maintenance with single icon library
Alex Holliday