- test_exchange_window and test_raw_exchange_gpu fine(): dense root becomes
a (12, 8) blocked root (fine(None) stays only for the dense reference test
that D2 retires);
- jets: G1/G3 compare blocked layouts against the FINE_BLOCKS[0] reference
(blocked root); the dense run is a separate leg D2 removes; G2 legacy
actuation vs Jet on the blocked reference; CPU fixtures use a blocked root;
- test_refinement_blocked_fine.raw reads every level through its layout;
- test_fine_surface_gpu: new test_fine_surface_blocked_matches_uniform_four_hops
(fine ROI after each of four hops vs the uniform 48^2 solver with the same
tolerances, blowing/suction mass sign from raw exchange, zero actuation ==
passive bit for bit); the cross-interface donor rejection passes tiles.
The dense hook/ledger/audit probes in test_fine_surface_four_hops and the
dense SoA fault tests stay until D2 retires them by name.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
