[v2.0] Phase 6: CI/CD — GitHub Actions for Rust backend

[fsecada01]

CI/CD pipeline for the Rust extension: lint, cross-platform test matrix, manylinux wheel builds, benchmark artifact.

Wiki: Phase 6 detail
Branch: feature/rust-backend

Tasks

• 6.1 .github/workflows/ci-rust.yml — lint-rust job: cargo fmt --check + cargo clippy --all-targets -- -D warnings
• 6.2 test job — matrix: ubuntu/macos/windows × Python 3.10/3.11/3.12; maturin develop --release + pytest
• 6.3 build-wheels job — PyO3/maturin-action@v1 with manylinux: auto; upload wheels as artifacts
• 6.4 benchmark job — runs tests/bench_splitting.py, uploads benchmark_results.txt as artifact
• 6.5 PyPI publish job — triggered on release; publishes manylinux wheels for zero-compile Linux installs

Notes

• lint-rust must gate test (no point running the matrix if fmt/clippy fails)
• manylinux wheels ensure Linux users get pre-compiled binaries (no Rust toolchain needed)