New top-level section covering the three-part shape every node type
follows — Node impl (lookbacks/eval/label with the C8 warm-up filter),
PrimitiveBuilder recipe (NodeSchema + positional build closure), and
rostering (project-side aura_project! vs std-side roster macro) — with
the aura-new Scale starter as the verbatim worked example and the five
fresh #236 nodes as arity-variant references. Cross-linked from the
op-script vocabulary note, project-layout, and the README.
closes#228
Brummel
753ab5f0ee