Build a real-time, photoreal 3D black hole in the browser (single HTML page, WebGL shaders, no external assets or libraries). Ray-traced gravitational lensing that bends the starfield and the Milky Way behind it, a blazing accretion disk with Doppler beaming (one side brighter and bluer), the Einstein ring and the photon ring, plus a glowing relativistic jet. The camera slowly orbits on its own; drag to orbit, scroll to fall toward the event horizon. Sliders for mass, disk temperature, spin and camera distance; a cinematic bloom and film grain. 60 fps. It should look unreal the moment it loads.