test: fixed three-level/two-region nested shear preset (nested_shear_n128)
Test-only opt-in. New shear_nested.py: fixed parent-frame rectangles
(L0->L1 (16,16,60,112),(68,24,112,120); L1->L2 (44,44,108,212),
(148,60,212,228)), exact leaves/hops/work/nu/tau, depth-3 + 4N-finest
generalization of the shear assessment (same summaries/screens/budgets),
bounded final macro snapshot writer/reader (packed ACTIVE leaves + rho/u,
metadata, sha256, 8 MiB cap; no populations/restart/time series).
run_case: --diagnostic nested_shear_n128 (U128, U512, constant/projected
R128 depth 3), --final-snapshot only for projected depth 3, shear_nested.py
path+hash pin. assess_shear_wave: assess_nested contract and CLI.
shear_wave.py and oracle.py byte-identical; old guards/defaults unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
