Major improvements to UnifiedPlayer:
1. GetFrameImage() now works when paused for responsive UI updates
2. Play() method properly starts FFmpeg process
3. Frame display loop runs continuously for smooth video display
4. Disabled audio temporarily to fix video playback fundamentals
5. Simplified FFmpeg command to focus on video stream only
Player now:
- Generates video frames correctly
- Shows video when paused
- Has responsive progress tracking
- Starts playback properly
Next steps: Re-enable audio playback once video is stable