Function log_kernel_bundle 

pub fn log_kernel_bundle(
    quadctx: &QuadratureContext,
    m: f64,
    mu: f64,
    sigma: f64,
    max_k: usize,
) -> Result<LogLognormalKernelBundle, EstimationError>

Builds a log-space kernel bundle for k = 0, 1, …, max_k at fixed (m, μ, σ).