fix clippy and fmt errors

Remove unused imports and fix formatting across ceno_zkvm and gkr_iop.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: kunxian-xia

ceno_zkvm/src/instructions/riscv/ecall/fptower_fp.rs

@@ -12,7 +12,6 @@ use gkr_iop::{
 };
 use itertools::{Itertools, izip};
 use multilinear_extensions::{ToExpr, util::max_usable_threads};
-use p3::matrix::Matrix;
 use rayon::{
     iter::{IndexedParallelIterator, IntoParallelRefIterator, ParallelIterator},
     slice::ParallelSlice,

ceno_zkvm/src/instructions/riscv/ecall/fptower_fp2_add.rs

@@ -11,7 +11,6 @@ use gkr_iop::{
 };
 use itertools::{Itertools, izip};
 use multilinear_extensions::{ToExpr, util::max_usable_threads};
-use p3::matrix::Matrix;
 use rayon::{
     iter::{IndexedParallelIterator, IntoParallelRefIterator, ParallelIterator},
     slice::ParallelSlice,

ceno_zkvm/src/instructions/riscv/ecall/fptower_fp2_mul.rs

@@ -11,7 +11,6 @@ use gkr_iop::{
 };
 use itertools::{Itertools, izip};
 use multilinear_extensions::{ToExpr, util::max_usable_threads};
-use p3::matrix::Matrix;
 use rayon::{
     iter::{IndexedParallelIterator, IntoParallelRefIterator, ParallelIterator},
     slice::ParallelSlice,

ceno_zkvm/src/instructions/riscv/ecall/keccak.rs

@@ -12,7 +12,6 @@ use gkr_iop::{
 };
 use itertools::{Itertools, izip};
 use multilinear_extensions::{ToExpr, util::max_usable_threads};
-use p3::matrix::Matrix;
 use rayon::{
     iter::{IndexedParallelIterator, ParallelIterator},
     slice::ParallelSlice,

ceno_zkvm/src/instructions/riscv/ecall/uint256.rs

@@ -13,7 +13,6 @@ use gkr_iop::{
 use itertools::{Itertools, chain, izip};
 use multilinear_extensions::{ToExpr, util::max_usable_threads};
 use num_bigint::BigUint;
-use p3::matrix::Matrix;
 use rayon::{
     iter::{IndexedParallelIterator, IntoParallelRefIterator, ParallelIterator},
     slice::ParallelSlice,

ceno_zkvm/src/instructions/riscv/ecall/weierstrass_add.rs

@@ -12,7 +12,6 @@ use gkr_iop::{
 };
 use itertools::{Itertools, izip};
 use multilinear_extensions::{ToExpr, util::max_usable_threads};
-use p3::matrix::Matrix;
 use rayon::{
     iter::{IndexedParallelIterator, IntoParallelRefIterator, ParallelIterator},
     slice::ParallelSlice,

ceno_zkvm/src/instructions/riscv/ecall/weierstrass_double.rs

@@ -12,7 +12,6 @@ use gkr_iop::{
 };
 use itertools::{Itertools, izip};
 use multilinear_extensions::{ToExpr, util::max_usable_threads};
-use p3::matrix::Matrix;
 use rayon::{
     iter::{IndexedParallelIterator, IntoParallelRefIterator, ParallelIterator},
     slice::ParallelSlice,

ceno_zkvm/src/scheme/prover.rs

@@ -16,7 +16,7 @@ use crate::scheme::{
 use either::Either;
 use itertools::Itertools;
 use mpcs::{Point, PolynomialCommitmentScheme};
-use multilinear_extensions::{Expression, Instance};
+use multilinear_extensions::Instance;
 use p3::field::PrimeCharacteristicRing;
 use std::iter::Iterator;
 use sumcheck::{
@@ -718,8 +718,7 @@ impl<
             // Prepare: deferred extraction for GPU, no-op for CPU
             self.device.prepare_chip_input(&mut task, witness_data);
 
-            let (proof, main_constraint_job) =
-                self.create_chip_proof(&mut task, transcript)?;
+            let (proof, main_constraint_job) = self.create_chip_proof(&mut task, transcript)?;
 
             Ok(ChipTaskResult {
                 task_id: task.task_id,

ceno_zkvm/src/scheme/verifier.rs

@@ -55,7 +55,6 @@ use multilinear_extensions::{
     virtual_polys::VirtualPolynomials,
 };
 
-
 use sumcheck::{
     frontload,
     structs::{IOPProof, IOPVerifierState, SumCheckSubClaim},

ceno_zkvm/src/tables/shard_ram.rs

@@ -25,7 +25,7 @@ use itertools::{Itertools, chain};
 use multilinear_extensions::{Expression, ToExpr, WitIn, util::max_usable_threads};
 use p3::{
     field::{Field, PrimeCharacteristicRing as FieldAlgebra},
-    matrix::{Matrix, dense::RowMajorMatrix},
+    matrix::dense::RowMajorMatrix,
     symmetric::Permutation,
 };
 use rayon::{