Docs: Improve Object3DNode.

[SamJB123]

Fix JSDoc for objectRadius to match implementation

Description

objectRadius returns a float, not vec3. A pure documentation fix - no impact on functionality.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	337.4 78.67	337.4 78.67	+0 B +0 B
WebGPU	553.89 153.48	553.89 153.48	+0 B +0 B
WebGPU Nodes	553.24 153.32	553.24 153.32	+0 B +0 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

	Before	After	Diff
WebGL	468.59 113.33	468.59 113.33	+0 B +0 B
WebGPU	628.86 170.19	628.86 170.19	+0 B +0 B
WebGPU Nodes	583.72 159.53	583.72 159.53	+0 B +0 B