Bootstrap Body3D as a single-file interactive 3D anatomy explorer

[Copilot]

This PR initializes the repository with a complete browser-only anatomy application in one index.html, using Three.js r158 via CDN importmap and no build/runtime tooling. It also establishes the project README with run model and scope.

• Single-file app foundation

  • Added index.html containing the full UI + rendering/runtime logic.
  • Wired Three.js r158 and OrbitControls through native importmap (threejs.org / examples/jsm).

• Application shell and interaction model

  • Implemented fixed 280px left sidebar (systems, view controls, active opacity, selected-part summary).
  • Implemented fixed top header (view title, reset camera, explode toggle, fullscreen).
  • Implemented right 320px slide-in info panel (part name, system badge, anatomy summary, key facts).

• 3D anatomy composition (no external assets)

  • Built a multi-system human figure entirely from primitives (Sphere, Cylinder, Capsule, Box, Torus, TorusKnot).
  • Structured parts as named meshes grouped by system for independent visibility/opacity control.
  • Added emissive neon material treatment and scene lighting to match the specified visual theme.

• Core behavior

  • Click-to-select part with synchronized left summary + right detail panel.
  • System toggles with active glow and ON/OFF state.
  • Camera presets (Front, Side, Top), orbit rotation toggle, reset camera, fullscreen.
  • Explode view animation via per-system offsets.

• Documentation bootstrap

  • Replaced README with the required project title and concise usage/features for opening index.html directly.

<script type="importmap">
{
  "imports": {
    "three": "https://threejs.org/build/three.module.js",
    "three/addons/": "https://threejs.org/examples/jsm/"
  }
}
</script>