Proves the design for true adaptive cell sizes: bottom-up coarsening of
the existing fine raster into power-of-two leaves (erosion-graded),
vectorized leaf-graph construction whose uniform limit reproduces the
production grid exactly (rel diff 0), solved with the production
assembly + AMG. On an adversarial 5.6M-cell geometry: 12x fewer
unknowns at -0.42% R (27 s -> 3 s) up to 26x at -2.1%.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
janik