feat: add real-time collaboration features with STOMP and SockJS

- Added @stomp/stompjs and sockjs-client dependencies for WebSocket communication.
- Updated routing for pastes to include new endpoint structure.
- Implemented real-time editing in PastePanel using STOMP for collaborative editing.
- Introduced NotificationModal for experimental mode warnings.
- Enhanced NavBar to display connection status.
- Refactored Home and PastePanel components to support new features and improve user experience.
- Updated error handling in DataContext to utilize ErrorContext for better error management.
- Added CSS animations for connection status indication.

vite.config.js

@@ -14,4 +14,7 @@ export default defineConfig({
       '@': path.resolve(__dirname, './src'),
     },
   },
+  define: {
+    global: 'window'
+  }
 })