CRITICAL SECURITY:
- Removed 3,019 pptx-env Python virtualenv files from public tracking
- Added pptx-env/ to .gitignore
- Note: Stripe live key ALREADY removed in previous commit a6dc277
NEW CONTRIBUTING.md (world-class):
- Research-quality standards matching README
- Honest about alpha status (108 failing tests)
- Correct contact: research@agenticgovernance.digital
- No fabricated features or cultural positioning
- Rigorous testing/documentation standards
- Clear research ethics section
RESULT: Public GitHub now properly cleaned and documented
