Function rope_yarn 

pub fn rope_yarn(
    gpu: &dyn GpuBackend,
    kernel: KernelHandle,
    q: DevicePtr,
    k: DevicePtr,
    positions: DevicePtr,
    seq_len: u32,
    num_q_heads: u32,
    num_kv_heads: u32,
    head_dim: u32,
    rotary_dim: u32,
    inv_freq: DevicePtr,
    theta: f32,
    stream: u64,
) -> Result<()>

2026-09-25: RoPE with frequencies from a precomputed inv_freq table ([rotary_dim/2] FP32); rope_forward_yarn ignores theta.