Function rms_norm_residual 

pub fn rms_norm_residual(
    gpu: &dyn GpuBackend,
    kernel: KernelHandle,
    input: DevicePtr,
    weight: &DenseWeight,
    output: DevicePtr,
    residual: DevicePtr,
    num_tokens: u32,
    hidden_size: u32,
    eps: f32,
    stream: u64,
) -> Result<()>

2026-09-25: output = rms_norm(input) and residual = input in one pass, one block per token row.