CI/CD pipeline (test, clippy, release binaries)

[ajianaz]

CI/CD Pipeline

Set up GitHub Actions workflows for continuous integration and release.

CI Workflow (.github/workflows/ci.yml)

• Triggers on push to main and pull requests
• Jobs: format check, clippy lint, test (with cargo-nextest), MSRV check
• Rust 1.85+ with caching

Release Workflow (.github/workflows/release.yml)

• Triggers on tag push (v*)
• Build matrix: linux-x86_64, linux-aarch64, macOS-x86_64, macOS-aarch64, windows-x86_64
• Use cross for Linux cross-compilation
• Upload binaries as GitHub Release assets
• Publish to crates.io

Acceptance Criteria

• CI passes on all PRs
• Release produces binaries for all 5 targets
• Binaries attached to GitHub Release
• crates.io publish works on tagged releases

[ajianaz]

✅ Implemented in initial release (v0.1.0) — commit b3f31c9