Function empirical_joint_entropy_bytes 

pub fn empirical_joint_entropy_bytes(x: &[u8], y: &[u8]) -> f64

Empirical (zero-order, IID) joint Shannon entropy H₀(X,Y) over aligned prefixes.

Treats aligned (x[i], y[i]) pairs as IID samples from a joint distribution over 65536 outcomes and returns the plug-in Shannon entropy.