Fix refresh_graph_schema to properly consume async generator

Co-authored-by: gkorland <753206+gkorland@users.noreply.github.com>

Author: Copilot

api/loaders/snowflake_loader.py

@@ -527,7 +527,10 @@ async def refresh_graph_schema(graph_id: str, db_url: str) -> Tuple[bool, str]:
                 prefix = graph_id
 
             # Reuse the existing load method to reload the schema
-            success, message = await SnowflakeLoader.load(prefix, db_url)
+            success = False
+            message = ""
+            async for progress_tuple in SnowflakeLoader.load(prefix, db_url):
+                success, message = progress_tuple
 
             if success:
                 logging.info("Graph schema refreshed successfully.")