Function q2tp_matvec 

pub fn q2tp_matvec(
    model: &Arc<CmfModel>,
    idx: usize,
    xs: &[f32],
    rows: usize,
    cols: usize,
    out: &mut [f32],
) -> bool

Single-token q2tp matvec through the ordinary (center=1.5) WGSL kernel.