I don't know, did the prior vibe-coded Zig code not ever have pointers aliased to data? Might be preserving semantics too well, if anything.

The Zig one uses raw pointers. These are bad and get out of hand quickly but at least don't have constraints like "you must never have two &mut on the same value". You may refer to c2rust to see how "semantics preserving transformation" without new UBs looks like.