pub fn post(
sub_layer_out: &[f32],
residual: &[Vec<f32>; 4],
post_gate: &[f32; 4],
comb: &[[f32; 4]; 4],
) -> [Vec<f32>; 4]Expand description
build_hc_post: re-injects the sub-layer’s single output back into
all hc streams, each scaled by its post gate and mixed with the
original (pre-merge) residual streams via the Sinkhorn comb
matrix: `out[dst] = sub_layer_out * post[dst] + sum_src(residual[src]
- comb[dst][src])`.