T-1081 review (Hoshe + Tyre): the seed_domain_discriminants_are_pinned test (the
D-224 guard that fails CI if a variant is renumbered — which would silently re-roll
every world's relief field) did not pin the new VoxelRelief = 11. Add the assertion.
Also fold Tyre's two Q-123 calibration notes into item 4: (i) sanity-check the
slope_q*3 + elev_q envelope on a synthetic high-slope body (both terms cap at 100);
(ii) the relief transect is a single diagonal slice (fine for isotropic fBm, revisit
if an anisotropic ridge field is added).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>