Only include user and assistant messages when generating titles

(again)

pkg/cmd/util/util.go

@@ -172,8 +172,11 @@ Example response:
 
 	var msgs []msg
 	for _, m := range messages {
+		switch m.Role {
+			case api.MessageRoleAssistant, api.MessageRoleUser:
 				msgs = append(msgs, msg{string(m.Role), m.Content})
 		}
+	}
 
 	// Serialize the conversation to JSON
 	conversation, err := json.Marshal(msgs)