Function get_random_element

pub fn get_random_element<'a, T>(
    slice: &'a [T],
    random: &GameRng,
) -> Option<&'a T>

Pick a uniformly-random element of slice, None when empty. Index is floor(random_f64() * len), clamped to len - 1 — one f64 draw, matching GameRng::random_index.