Fix headless video playback: prevent infinite looping and enable proper video transitions

- Modified video input to not loop intro/match/result videos (only black screen loops)
- Added automatic transition to black screen when non-looping videos end
- Restart HLS process during video switches for clean segment generation
- Added robust error handling for connection resets during transitions
- Increased HLS playlist size and disabled caching for smoother transitions
- Fixed video switching logic to ensure proper HLS content updates