`provekit/backend/bn254/src/mavros_prove`: make field-generic and fold into `WhirR1CSProver<P>` when the Mavros

[recmo]

On 2026-07-13 in 61744fa “Merge pull request #470 from worldfnd/feat/base-field-witness-commit”:

make field-generic and fold into WhirR1CSProver<P> when the Mavros
VM is field-agnostic.

//! Mavros WHIR proving for bn254. The Mavros VM's automatic-differentiation
//! pass returns `ark_bn254::Fr`, so this proving path is bn254-specific; it
//! composes the generic proving primitives from `provekit-prover`
//! (`run_zk_sumcheck_prover`, `prove_from_alphas`).
//!
//! TODO: make field-generic and fold into `WhirR1CSProver<P>` when the Mavros
//! VM is field-agnostic.

use {
    crate::{Bn254Field, FieldElement, TranscriptSponge},
    anyhow::{ensure, Result},
    mavros_artifacts::{ConstraintsLayout, WitnessLayout},

From provekit/backend/bn254/src/mavros_prove.rs:6