Update app.py

app.py

@@ -578,7 +578,7 @@ class BotanistAssistant:
         
         # Stream additional assistant responses if available
         if "choices" in api_response:
-            for choice in api_response["choices"]:
+            for choice in api_response["choices"][0]:
                 if "message" in choice and "content" in choice["message"]:
                     yield choice["message"]["content"]