risk_budget_forward: h_s2 || isv_signals[8] || predicted_error[1]. risk_budget_backward: wider stride j*(SH2+9), grads for ISV+error cols. w_risk_fc grows from AH*SH2=32768 to AH*(SH2+9)=33920 (+1152 elems). risk_aligned_count and offset callers updated atomically. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>