Fix prepdocs to properly close async clients

Author: pamelafox

.github/chatmodes/fixer.chatmode.md

@@ -26,6 +26,10 @@ You MUST check task output readiness before debugging, testing, or declaring wor
 	- If watchers seem stuck or output stops updating, stop the tasks and run the "Development" task again.
 - To interact with a running application, use the Playwright MCP server
 
+## Running Python scripts
+
+If you are running Python scripts that depend on installed requirements, you must run them using the virtual environment in `.venv`.
+
 ## Committing the change
 
 When change is complete, offer to make a new branch, git commit, and pull request.

app/backend/prepdocs.py

@@ -596,5 +596,14 @@ async def main(strategy: Strategy, setup_index: bool = True):
             content_understanding_endpoint=os.getenv("AZURE_CONTENTUNDERSTANDING_ENDPOINT"),
         )
 
-    loop.run_until_complete(main(ingestion_strategy, setup_index=not args.remove and not args.removeall))
-    loop.close()
+    try:
+        loop.run_until_complete(main(ingestion_strategy, setup_index=not args.remove and not args.removeall))
+    finally:
+        # Gracefully close any async clients/credentials to avoid noisy destructor warnings
+        try:
+            loop.run_until_complete(blob_manager.close_clients())
+            loop.run_until_complete(openai_client.close())
+            loop.run_until_complete(azd_credential.close())
+        except Exception as e:
+            logger.debug(f"Failed to close async clients cleanly: {e}")
+        loop.close()

docs/multimodal.md

@@ -44,7 +44,7 @@ With this feature enabled, the following changes are made:
    azd env set AZURE_SEARCH_INDEX multimodal-index
    ```
 
-   Then run the data ingestion process again to re-index the data:
+   Then delete the `.md5` hash files in the data folder(s) and run the data ingestion process again to re-index the data:
 
    Linux/Mac: