Fix NTT test lint violations

[erdkocak]

This PR fixes style-linter failures in the univariate NTT files and tests.

Changes

• wrap long lines in the NTT sources and benchmark
• remove banned native_decide usage
• convert NTT regression checks to #guard-based executable tests

[doran2728]

Good job, LGTM.

[github-actions]

Build Timing Report

• Commit: f971ccb
• Message: Merge a56b9a6 into e43b06a
• Ref: linter-fixes
• Comparison baseline: e43b06a from merge-base on master.
• Measured on ubuntu-latest with /usr/bin/time -p.
• Commands: clean build rm -rf .lake/build && lake build; warm rebuild lake build; test path lake test.

Measurement	Baseline (s)	Current (s)	Delta (s)	Status
Clean build	256.14	263.02	+6.88	ok
Warm rebuild	1.82	1.80	-0.02	ok
Test path	22.05	23.23	+1.18	ok

Incremental Rebuild Signal

• Warm rebuild saved 261.22s vs clean (146.12x faster).

This compares a clean project build against an incremental rebuild in the same CI job; it is a lightweight variability signal, not a full cross-run benchmark.

Slowest Current Clean-Build Files

Showing 20 slowest current targets, with comparison against the selected baseline when available.

Current (s)	Baseline (s)	Delta (s)	Path
85.00	84.00	+1.00	CompPoly/Fields/Binary/BF128Ghash/XPowTwoPowModCertificate.lean
52.00	55.00	-3.00	CompPoly/Fields/Binary/Tower/Abstract/Basis.lean
49.00	49.00	+0.00	CompPoly/Bivariate/ToPoly.lean
29.00	28.00	+1.00	CompPoly/Univariate/Raw/Proofs.lean
28.00	31.00	-3.00	CompPoly/Fields/Binary/BF128Ghash/Impl.lean
24.00	21.00	+3.00	CompPoly/Fields/Binary/AdditiveNTT/NovelPolynomialBasis.lean
23.00	21.00	+2.00	CompPoly/Univariate/Lagrange.lean
21.00	23.00	-2.00	CompPoly/Fields/Binary/Tower/Support/Preliminaries.lean
20.00	17.00	+3.00	CompPoly/Fields/Binary/AdditiveNTT/Intermediate.lean
20.00	12.00	+8.00	CompPoly/Multivariate/Unlawful.lean
17.00	18.00	-1.00	CompPoly/Univariate/Quotient/Core.lean
16.00	16.00	+0.00	CompPoly/Fields/Binary/AdditiveNTT/Domain.lean
16.00	16.00	+0.00	CompPoly/Univariate/Basic.lean
15.00	13.00	+2.00	CompPoly/Fields/Binary/Common.lean
14.00	12.00	+2.00	CompPoly/Fields/Binary/AdditiveNTT/Correctness.lean
14.00	15.00	-1.00	CompPoly/Fields/Binary/Tower/Abstract/Core.lean
13.00	10.00	+3.00	CompPoly/Fields/Binary/Tower/TensorAlgebra.lean
11.00	9.70	+1.30	CompPoly/Fields/Binary/Tower/Abstract/Split.lean
11.00	11.00	+0.00	CompPoly/Fields/Binary/BF128Ghash/XPowTwoPowGcdCertificate.lean
11.00	10.00	+1.00	CompPoly/Multivariate/MvPolyEquiv/Instances.lean