Update app.py

app.py

@@ -294,7 +294,18 @@ if research_button and topic:
             
                 return sources
 
-
+            
+            all_sources, retries = [], 0
+            while retries < 3:
+                all_sources = fetch_all_sources()
+                if all_sources:
+                    break
+                retries += 1
+                time.sleep(2)
+            
+            if not all_sources:
+                raise ValueError("❌ No sources found.")
+            
             merged = merge_duplicates(all_sources)
             merged = sort_sources_chronologically(merged)