This is a one-shot benchmark. Work autonomously and do not ask questions. Create the complete final artifact as index.html in the current empty directory. There will be no second attempt and no feedback-driven corrections. You may test and inspect your own work during this single run. The artifact must open directly in a modern browser without a build step. CDN imports for Three.js and hand tracking are allowed, but do not use external models, textures, images, or other content assets.

Create a real-time interactive 3D particle system in Three.js. The system should use the camera to track hand gestures and dynamically control particle behaviour, including expansion and colour changes.

Render 100,000 GPU particles.

Recognize both hands.

Distance between hands controls scale.
Hand rotation rotates the particle object.
Closed fist causes gravitational collapse.
Open palm causes an explosion.
Finger movement generates particle trails.

Morph smoothly between galaxy, Saturn, DNA helix, human heart, flower and black hole.