Revert "v8"

This reverts commit bec673d3d87e85af4d321416cf2f782d1d3e8612.

app.py

@@ -790,9 +790,6 @@ async def stream_agent_response(question: str, chat_history: List[List[str]]) ->
             logger.info("No chart generated for this turn.")
         else:
             logger.info("Returning a chart figure to UI.")
-        logger.info(
-            f"Returning from stream_agent_response: msg_len={len(message_content) if isinstance(message_content, str) else 'NA'}, chart={chart_fig is not None}"
-        )
         return message_content, chart_fig
 
 # Custom CSS for the app
@@ -1058,14 +1055,15 @@ def create_application():
             if isinstance(result, tuple) and len(result) == 2:
                 assistant_message, chart_fig = result
             elif isinstance(result, dict) and "content" in result:
-                assistant_message, chart_fig = result.get("content", ""), None
+                assistant_message, chart_fig = result["content"], None
+            elif isinstance(result, str):
+                assistant_message, chart_fig = result, None
             else:
-                # Fallback: coerce any unexpected result to string as assistant message
-                try:
-                    assistant_message = str(result) if result is not None else ""
-                except Exception:
-                    assistant_message = ""
-                chart_fig = None
+                logger.error("stream_agent_response returned unexpected value: %r", result)
+                assistant_message, chart_fig = (
+                    "## ❌ Error\n\nNo se recibió una respuesta válida del agente.",
+                    None,
+                )
 
             # Append assistant message back into messages history
             chat_history.append({"role": "assistant", "content": assistant_message})