NodeMaterialObserver: track renderId per render object instead observer

[arodic]

Related issue: #32926

NodeMaterialObserver: track renderId per render object instead of per observer

Multiple render objects sharing the same observer (same cache key) would
incorrectly skip geometry updates because the first object processed would
set the shared renderId, causing subsequent objects to fall through to
equals() which only checked attribute.version, not actual attribute identity.

When setAttribute()/setIndex() replaces an attribute with a new object
that has the same version number, the cache incorrectly treated it as
unchanged, causing GPU buffer creation to be skipped and a crash on render.

Changes:

• Move renderId from observer-level to per-render-object data
• All render objects now get the fast renderId path (performance Impact should be positive if any - but havent checked)

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	359.21 85.29	359.21 85.29	+0 B +0 B
WebGPU	617.06 171.62	623.7 173.38	+6.64 kB +1.77 kB
WebGPU Nodes	615.64 171.37	622.28 173.13	+6.64 kB +1.76 kB

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	490.47 119.49	490.47 119.49	+0 B +0 B
WebGPU	690.36 186.56	690.36 186.56	-7 B +0 B
WebGPU Nodes	639.75 173.96	639.74 173.96	-7 B +0 B