Function q8_gemv_applies 

pub fn q8_gemv_applies(spec: &MatmulSpec, target: &SpatialTarget) -> bool

Whether a product over a Q8_0 weight folds on target: up to a tile’s rows, whole Q8_0 blocks of K, on a square tile as tall as a Q8_0 block. Its columns are the weight’s column tiles, the last padded with zero columns as every tensor’s last tile is — a tensor-parallel chip’s 24 of a gate’s 48 heads, a width of 40 — so the pad’s values and scales are zero and its sums land only in the result’s own pad.