Fix: Add missing src/utils/video.py module (fixes #2)

- Created src/utils/video.py with VideoEnhancer class
- Added has_audio_stream() and exec_cmd() utility functions
- Updated VERSION to 1.0.1
- Added release notes for v1.0.1

This fixes the ImportError that prevented the application from starting.

PresentaPulse v1.0.0 - First Major Release