HNSW

- why would someone add nearest neighbor search to plan9? -

[hnsw source] initial release : Sept 30, 2026

libhnsw for 9front. because no one can stop me.

`bind -a ./include /sys/include`

`bind -a ./src /sys/src/`

`cd /sys/src/libhnsw ; mk ; mk install`

see header for definitions for now. man page when i get around to it, because frankly who the heck wants this?