papers/arxiv-penrose: add Penrose-driven illustration pipeline
New paper that demonstrates a data-driven diagram pipeline for the AC
papers stack: an AC-specific Penrose domain (Piece, Library, Function,
Repo, Category) with three styles (lineage, set membership, library
graph), plus build-figures.mjs that introspects the live repo (378
disks, 78 lib modules, 12 KidLisp categories, 4 successive repos) and
emits matching .substance files. Ships deterministic TikZ fallbacks so
the paper compiles without @penrose/roger on PATH.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>