SyncPlayer 1.6.5 - ffmpeg included, full-quality downloads

Added

• ffmpeg is bundled with the Windows installer, so downloads reach full quality: yt-dlp
  needs it to merge the separate video and audio streams that anything above roughly
  720p is published as. Unchecking it (or --no-ffmpeg) omits it, which caps downloads
  at single-file quality.
• The updater installs ffmpeg for installations that do not have it.