Function aes_sbox_kernel 

pub fn aes_sbox_kernel(value: b8) -> b8

Exhaustive combinational AES S-box for synthesis as fixed Boolean logic.

Input and output are one byte. A 256-way match is the most direct way to tell RHDL “this is a fixed table”; synthesis turns it into LUT logic. The chain-step lane uses ROMs from crate::aes_table instead, so the memory type can be chosen per S-box; this kernel serves the general Haraka512Pipeline and the small equivalence kernels.