Change entity type formatting from title case to lowercase without spaces

lightrag/operate.py

@@ -354,8 +354,8 @@ async def _handle_single_entity_extraction(
             )
             return None
 
-        # Captitalize first letter of entity_type
-        entity_type = entity_type.title()
+        # Remove spaces and convert to lowercase
+        entity_type = entity_type.replace(" ", "").lower()
 
         # Process entity description with same cleaning pipeline
         entity_description = sanitize_and_normalize_extracted_text(record_attributes[3])