Refactor Dropdown Handlers and Update WordPress Integration

- Updated dropdown onChange handlers across multiple components to use direct value passing instead of event target value for improved clarity and consistency.
- Changed `url` to `site_url` in WordPress integration configuration for better semantic clarity.
- Enhanced Vite configuration to include `fast-deep-equal` for compatibility with `react-dnd`.
- Updated navigation paths in `SiteContentEditor` and `SiteList` for consistency with new routing structure.

frontend/src/components/sites/WordPressIntegrationCard.tsx

@@ -17,8 +17,7 @@ interface WordPressIntegration {
   sync_status: 'success' | 'failed' | 'pending';
   last_sync_at?: string;
   config_json?: {
-    url?: string;
-    username?: string;
+    site_url?: string;
   };
 }
 
@@ -75,7 +74,7 @@ export default function WordPressIntegrationCard({
                 WordPress Integration
               </h3>
               <p className="text-sm text-gray-600 dark:text-gray-400">
-                {integration.config_json?.url || 'WordPress Site'}
+                {integration.config_json?.site_url || 'WordPress Site'}
               </p>
             </div>
           </div>