loop: add todo checklist

This should improve Sketch's executive function and user communication.
diff --git a/cmd/go2ts/go2ts.go b/cmd/go2ts/go2ts.go
index cc97c6b..a888be1 100644
--- a/cmd/go2ts/go2ts.go
+++ b/cmd/go2ts/go2ts.go
@@ -57,6 +57,8 @@
 		loop.ToolCall{},
 		llm.Usage{},
 		server.State{},
+		server.TodoItem{},
+		server.TodoList{},
 		loop.MultipleChoiceOption{},
 		loop.MultipleChoiceParams{},
 		git_tools.DiffFile{},