Revert "memory chatbot upgrade"

This reverts commit fa719ce6f287576c7135b09bb95b0f48bb925279.

app.py

@@ -468,23 +468,19 @@ async def stream_agent_response(question: str, chat_history: List[List[str]]) ->
             f"3. El modelo de lenguaje esté disponible\n\n"
             f"Error: {agent_error}"
         )
-        return error_msg, None, None
+        return error_msg, None
         
     # Update the agent's memory with the full conversation history
     try:
-        # Hydrate agent memory only if it's empty; do NOT clear existing memory.
+        # Rebuild agent memory from chat history pairs
         if hasattr(agent, 'memory') and agent.memory is not None:
-            try:
-                existing_messages = getattr(getattr(agent.memory, 'chat_memory', None), 'messages', []) or []
-            except Exception:
-                existing_messages = []
-            if not existing_messages and chat_history:
-                for pair in chat_history:
-                    try:
-                        user_prev, bot_prev = pair[0], pair[1] if len(pair) > 1 else ""
-                        agent.memory.save_context({"input": user_prev}, {"output": bot_prev})
-                    except Exception:
-                        continue
+            agent.memory.clear()
+            for i in range(0, len(messages)-1, 2):  # (user, assistant)
+                if i+1 < len(messages):
+                    agent.memory.save_context(
+                        {"input": messages[i].content},
+                        {"output": messages[i+1].content}
+                    )
     except Exception as e:
         logger.error(f"Error updating agent memory: {str(e)}", exc_info=True)
     
@@ -730,7 +726,7 @@ async def stream_agent_response(question: str, chat_history: List[List[str]]) ->
         error_msg = f"## ❌ Error\n\nOcurrió un error al procesar tu solicitud:\n\n```\n{str(e)}\n```"
         logger.error(f"Error in stream_agent_response: {str(e)}", exc_info=True)
         # Return error message and no chart
-        return error_msg, None, None
+        return error_msg, None
 
 # Custom CSS for the app
 custom_css = """