separate and improve conversation agent

backend/app.py

@@ -15,6 +15,8 @@ import agent as agent_mod
 from server import start_server
 from chat import ChatView, Message
 
+from agents.conversation import ConversationAgent
+
 MESSAGE_PAGE_SIZE = 32
 
 class ChatContext:
@@ -41,7 +43,7 @@ class App:
         # `Agent` is the kind 'basic', will be class `BasicAgent` in the future
         self.agent_classes = [
             agent_mod.BasicAgent,
-            agent_mod.ConversationAgent,
+            ConversationAgent,
             agent_mod.Llama8bAgent,
             agent_mod.CoderV1Agent,
             agent_mod.ToolUsingAgent,