Integrated design spec for the post-A/B redesign: Kendall sigma BCE
(A), L2 anchor on horizon tokens + shared Q (B), horizon-token
K-prepend replacing per-horizon Q_h (C), regime-aware MoE gate (D),
and inverted-axis attention pass (E). Bundled per
pearl_no_deferrals_for_complementary_fixes — all five axes have
orthogonal architectural scope and independent kill criteria.
Spec drops the C21-C25 per-horizon Q_h path (falsified by sweep
2026-05-18: mean_auc -0.019 vs single-Q baseline) and migrates the
existing init buffers into the new horizon-tokens prefix.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
1c2ee1d7c3