Update src/ai_agent/ui/components.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: qchapp

src/ai_agent/ui/components.py

@@ -341,7 +341,8 @@ def handle_chat(message: str, history: List[dict], files: List, state_dict: dict
 
             except Exception as e:
                 log.exception("Error in chat handler")
-                history.pop()  # Remove thinking indicator
+                if history:
+                    history.pop()  # Remove thinking indicator
                 error_msg = {
                     "role": "assistant",
                     "content": (