Add 'system' messages to format_prompt

app.py

@@ -252,6 +252,8 @@ def format_prompt(messages):
             prompt += f"User: {msg['content'].strip()}\n"
         elif role == "assistant":
             prompt += f"Assistant: {msg['content'].strip()}\n"
+        elif role == "system":
+            prompt += f"System: {msg['content'].strip()}\n"
     prompt += "Assistant:"
     return prompt