Function py_ph_route_waveguides 

pub(crate) fn py_ph_route_waveguides<'py>(
    py: Python<'py>,
    adjacency_flat: Vec<f64>,
    n: usize,
    pitch_um: f64,
    loss_db_per_cm: f64,
) -> PyResult<Py<PyAny>>

Route waveguides on a mesh topology (Rust-accelerated).