Function fp8_gemm_act_weight_t_blkscaled_ldc 

pub fn fp8_gemm_act_weight_t_blkscaled_ldc(
    act_fp8: u64,
    act_scale: u64,
    weight_fp8: u64,
    weight_block_scale: u64,
    out: u64,
    m: u32,
    n: u32,
    k: u32,
    ldc: u32,
    stream: u64,
) -> Result<()>

2026-09-25: fp8_gemm_act_weight_t_blkscaled with output rows ldc BF16 elements apart: D is column-major [N, m] with leading dimension ldc, i.e. row-major [m, N] with row pitch ldc. The multi-seq decode Q/K/V projections use it to write each row into its sequence’s slot of the QKV buffer (w8a8_decode.rs qkv_decode_w8a8_plans, ldc = per_seq_qkv in BF16 elements).

All m rows are written, padding rows included, so the output extent is (m - 1) * ldc + n elements; callers bound it against their buffer with metrale_model_layers::layers::ops::strided_out_extent_elems.

Fails before calling cuBLASLt when ldc < n.