Function q2_0_gemv_vec_batchm 

pub fn q2_0_gemv_vec_batchm(
    gpu: &dyn GpuBackend,
    kernel: KernelHandle,
    input: DevicePtr,
    weight: &PackedQ2Weight,
    output: DevicePtr,
    m: u32,
    stream: u64,
) -> Result<()>

2026-09-25: Batched Q2_0 GEMV for any m: C[M,N] = A[M,K] @ dequant(B)^T, A and C row-major BF16. Each weight word is read once per launch and applied to every staged row.

m is split into launches of at most Q2_BATCHM_MAX_M rows, with the input and output pointers advanced by whole rows; m <= 8 is one launch, and m == 0 launches nothing.