fix(windows): enhance Windows compatibility and test robustness

- Implement robust win32api detection with importlib.util.find_spec
- Add cross-platform cache directory fallback mechanisms
- Improve test compatibility for Windows, macOS, and Linux
- Create dedicated Windows compatibility test suite
- Add new CI workflow with improved error handling

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: jamesbrink