Client overlay: red = local · blue = remote · green = hit box · click HUD (bottom-left). In-page (fade 2s): blue = event.target · red = event.currentTarget / delegate host.
Encode/decode overlay on video.
Positive delays video (if lips lead audio). Saved per tab.
Mouse clicks via Chrome DevTools instead of the X11 pointer.
Multitouch uses a kernel uinput device and Xorg (not Xvfb). Requires install-uinput-touch.sh as root.