"lazy" should be deprecated or rewritten or something

- for some reason, lazy kinda pretends to be shaped like a signal, but it cannot be used to trigger effects, and so it doesn't make sense
- i'm pretty sure the lazy implementation is way overcomplicated
- i think we should remove lazy as it is, and maybe make a new lazy fn that is much simpler, i think it's basically just a closure with a dirty flag and an effect to set it