Function conjectured_error 

pub fn conjectured_error(regime: &FriRegime, shape: &InstanceShape) -> ErrorBits

Conjectured low-degree-test soundness (random-words, [2025/2010] §1.5).

b = num_queries · (−log2(ρ + η)) + query_pow, with η ≈ (log2(e/ρ) · ρ) / log2(q).