Release v0.1.2: Refactor tests, add examples, and update metadata

- Bump package version to 0.1.2
- Update project URL and contact info in setup.py and README
- Fix documentation links for PyPI compatibility
- Refactor test suite structure: distinct folders for text, image, audio
- Add new tests for provenance, AASIST, and breathing signals
- Add advanced multimodal usage example
- Cleanup MANIFEST.in and existing test files