Add CI workflow for automated testing

[vbergeron]

Summary

This PR adds a GitHub Actions CI workflow to automatically build and test the project on pull requests and pushes to main.

Key Changes

• Added .github/workflows/ci.yml with automated CI pipeline that:
  • Runs on pull requests, pushes to main, and manual workflow dispatch
  • Tests both default and all-features configurations
  • Uses matrix strategy to test feature combinations in parallel
  • Includes build and test steps for the entire workspace
  • Caches Rust dependencies between runs for faster CI execution
  • Uses concurrency controls to cancel in-progress runs when new commits are pushed

Implementation Details

• Leverages dtolnay/rust-toolchain@stable for consistent Rust version
• Employs Swatinem/rust-cache@v2 to cache build artifacts per feature configuration
• Runs on ubuntu-latest with fail-fast: false to ensure all feature combinations are tested even if one fails
• Conditionally applies --all-features flag based on matrix variable for clean test invocation

https://claude.ai/code/session_01NddcEhWQKEr5svxX3BcgFm