pub fn expand_blocks_to_groups(
spec: &GroupLayout,
reqs: &[BlockReadRequest],
) -> Vec<ReadRequest>Expand description
2026-09-25: Expand each block request into its 2·nkv per-head requests,
ordered K(kh), V(kh) for kh in 0..nkv, with device destinations
dst + kh·gs (K) and dst + (nkv + kh)·gs (V). The default read_blocks
and read_blocks_async fan out through it.