Function eval_wprog_config 

pub fn eval_wprog_config(cfg: &WProgConfig, params: &[i64]) -> i64

Interpret the flat config exactly as the RTL will: a register file seeded with params, a block-walk over the terminator graph, each block computing its cells (Arith/Select) over its live-in registers + prior cell values, committing its register writes, and branching on its terminator. Proven bit-identical to run_program_cfg_on_grid (≡ the VM) — the reference the whole-program RTL is checked against.