agent chat now returns tool usage info

cli/src/main.rs

@@ -44,7 +44,7 @@ async fn chat_loop(mut human_interface: impl HumanInterface, mut agent_chat: Age
     loop {
         let user_message = human_interface.expect_user_message().await.unwrap();
         let immutable_interface = &human_interface;
-        let agent_message = agent_chat
+        let (agent_message, _) = agent_chat
             .message(user_message, async |mcp_server_name, tool_name| {
                 immutable_interface
                     .ask_for_permission(mcp_server_name, tool_name)