Scheduled Windows and macOS run #134

Why: path handling (normalizeFilePath, extractBasePath) and starting Java differ by OS, and z3's native libraries are platform specific. Running every OS on each PR is slow, but a periodic run catches platform breakage.

What: a weekly scheduled workflow (plus manual workflow_dispatch) that runs the unit and integration tests on windows-latest and macos-latest, without xvfb.

References:

• vscode-go runs its full test suite daily on Ubuntu, Windows and macOS: https://github.com/golang/vscode-go/blob/master/.github/workflows/test-long-all.yml
• vscode-java runs its PR checks on macOS and Ubuntu: https://github.com/redhat-developer/vscode-java/blob/main/.github/workflows/pr-verify.yml