render-core: press's per-unit walk extracted, byte-parity proven

The Stage 3 prerequisite (ZERO-STATIC.md): the pure-compute render loop (param walks, proc.render block loops, mono-legato, insert chains, merged active intervals) moves to faust/render-core.js

▶ Play it: Highway Heat Death — where the synthesis is the identity, not the decoration https://stellate.app/?genre=synthwave&seed=9171&path=859.9909,878.9942,840.9942&xdur=13.122

b3273cf https://github.com/aboard-io/stellate/commit/b3273cf383d5eedafd432f7e981509f443dc0a41