Function qsa_block_pool 

pub fn qsa_block_pool(
    gpu: &dyn GpuBackend,
    kernel: KernelHandle,
    raw_keys: DevicePtr,
    k_norm_w: DevicePtr,
    block_keys: DevicePtr,
    first_block: u32,
    n_new: u32,
    ratio: u32,
    hd: u32,
    rot: u32,
    theta: f32,
    eps: f32,
    stream: u64,
) -> Result<()>

2026-09-25: Pool n_new newly complete blocks starting at first_block: the mean of ratio raw keys, then RMSNorm scaled by 1 + w, then rope at the block’s first token position. Returns without launching when n_new == 0.