feat: Add initialization progress WebSocket and UI components

- Implement WebSocket route for initialization progress updates
- Create initialization component with progress bar and stages
- Add styles for initialization UI
- Update base template to include initialization component
- Enhance model scanner to broadcast progress during initialization

static/css/style.css

@@ -19,6 +19,7 @@
 @import 'components/bulk.css';
 @import 'components/shared.css';
 @import 'components/filter-indicator.css';
+@import 'components/initialization.css';
 
 .initialization-notice {
     display: flex;