Small improvements

frontend/src/lib/scraper/strategies/linkExtractor.ts

@@ -78,6 +78,10 @@ export function extractResponsiveImage(
         return { url, width };
       });
       
+      if (sources.length === 0) {
+        return img.attr('src') || '';
+      }
+      
       const largest = sources.reduce((prev: any, current: any) => 
         prev.width > current.width ? prev : current
       );