collapse in torch is bit-exact with the hc_collapse kernel and a faster graph (512 rows: 0.15 vs 1.73 ms
standalone). post_torch (the kernel's operation order) is bit-equal standalone but rounds differently fused
in the layer graph, so it is opt-in. Tiny golden 9/9 with collapse. bind_cpu receives the physical core id;
_neuron_bind_cpus indexed CUDA_VISIBLE_DEVICES with it again (broke runs on cores other than 0..n).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>