Add GitHub Action to build and test on Windows, macOS, and Linux #20
Description
Summary
Add a GitHub Actions workflow that runs build and test steps across Windows, macOS, and Linux to ensure cross-platform compatibility and prevent OS-specific regressions on Pull Requests.
Goals
- Validate the project builds successfully on:
- Ubuntu (Linux)
- Windows
- macOS
- Catch OS-specific issues early (path handling, scripts, environment differences).
- Increase contributor confidence regardless of development environment.
Non-Goals
- OS-specific feature testing (e.g. platform-dependent behavior).
- Supporting legacy OS versions beyond standard GitHub runners.
- Adding complex platform-specific logic to the codebase.