I want a display manager that shows the desktop as the background, instead of a background image or video. I'm thinking of auto-logging in on boot, and adding another startup command to Hyprland to lock the desktop and show the display manger. My searches didn't yield anything. The closest I could find is hyprlock which blurs the desktop, but that's just a lock screen & not a proper display manager.
That's a compositor's job. Look at what compositor you have and how to enable this.