Hide seen YouTube videos that are currently visible on screen (pretty printed to help browser debuggers)

hide_seen_youtube_videos.js

for (const videoThumbnailThing of document.querySelectorAll("ytd-grid-video-renderer")) {
  const videoThumbnailPlayback = videoThumbnailThing.querySelector("ytd-thumbnail-overlay-resume-playback-renderer");
  if (videoThumbnailPlayback != null) {
    videoThumbnailThing.style.display = "none";
  }
}