brush rendering is now completely client-side.
the server only receives edits the client would like to do, in the form of PNG images of chunks, that are then composited onto the wall
known issue: it is possible to brush up against the current 256 chunk edit limit pretty easily.
I'm not sure it can be solved very easily though. the perfect solution would involve splitting up the interaction into multiple edits, and I tried to do that, but there's a noticable stutter for some reason that I haven't managed to track down yet.
so it'll be kinda crap for the time being.
the goal is to rewrite haku completely, starting with the VM---because it was the most obvious point of improvement
the reason is because Rust is kinda too verbose for low level stuff like this. compare the line numbers between haku1 and haku2's VM and how verbose those lines are, and it's kind of an insane difference
it also feels like Zig's compilation model can work better for small wasm binary sizes
and of course, I also just wanted an excuse to try out Zig :3
