feat: expose plonky2 recursion to the user

plonky2x/core/src/frontend/recursion/mod.rs

@@ -1,4 +1,5 @@
 pub mod extension;
 pub mod fri;
 pub mod hash;
+pub mod plonky2_proof;
 pub mod polynomial;

plonky2x/core/src/frontend/recursion/plonky2_proof.rs

@@ -0,0 +1,26 @@
+use crate::frontend::recursion::extension::ExtensionVariable;
+use crate::frontend::recursion::fri::proof::FriProofVariable;
+use crate::frontend::recursion::hash::MerkleCapVariable;
+use crate::prelude::Variable;
+pub struct ProofWithPublicInputsVariable<const D: usize> {
+    pub proof: ProofVariable<D>,
+    pub public_inputs: Vec<Variable>,
+}
+
+pub struct ProofVariable<const D: usize> {
+    pub wires_cap: MerkleCapVariable,
+    pub plonk_zs_partial_products_cap: MerkleCapVariable,
+    pub quotient_polys_cap: MerkleCapVariable,
+    pub openings: OpeningSetVariable<D>,
+    pub opening_proof: FriProofVariable<D>,
+}
+
+pub struct OpeningSetVariable<const D: usize> {
+    pub constants: Vec<ExtensionVariable<D>>,
+    pub plonk_sigmas: Vec<ExtensionVariable<D>>,
+    pub wires: Vec<ExtensionVariable<D>>,
+    pub plonk_zs: Vec<ExtensionVariable<D>>,
+    pub plonk_zs_next: Vec<ExtensionVariable<D>>,
+    pub partial_products: Vec<ExtensionVariable<D>>,
+    pub quotient_polys: Vec<ExtensionVariable<D>>,
+}