Summary

• Adds a test-windows CI job that runs on windows-latest and installs Octave via choco install octave
• Uses pwsh shell to override the global bash -leu default
• Adds test-windows to the tests_check branch protection job
• Fixes duplicate [dependency-groups] section in pyproject.toml that was causing codespell and uv lock to fail
• Regenerates uv.lock after the pyproject.toml fix

Test plan

• Verify test-windows job passes on GitHub Actions
• Verify tests_check branch protection still passes with the new job included