Fix location_start/location_end validation error: convert to strings

app.py

@@ -283,8 +283,8 @@ async def search(request: SearchRequest):
                         "source_title": metadata['source_title'],
                         "content": metadata['content'],
                         "similarity": float(similarity),
-                        "location_start": metadata.get('location_start'),
-                        "location_end": metadata.get('location_end')
+                        "location_start": str(metadata.get('location_start', '')),
+                        "location_end": str(metadata.get('location_end', ''))
                     })
 
             total_searched += len(similarities)