The canonical graph is a forest of 24 roots spread across generations 0-4.
Packing every root at tree-depth 0 stacked all of them horizontally even when
they sit at different generations (different y), blowing the canvas out to
~9660px. Indexing the contour by absolute level (the rank buildLayout already
passes as level) lets unrelated roots at different generations share x-columns,
and keeps the no-overlap guarantee per-row. level falls back to tree depth when
omitted, so the abstract tidyTree tests are unaffected.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
New domain-agnostic bottom-up tidy-tree module (Reingold-Tilford contour pack)
operating on abstract { id, width, children } nodes — zero generated-API
imports. First rung of the TDD ladder: a single leaf lays out at x=0. The full
contour/centring machinery is in place; subsequent commits add tests that
exercise it.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
