Nodes: fix type errors

[s-rigaud]

Description

I tried running Typescript to check the coherence of all the types inside the nodes folder. I found some updates to improve the existing code and fix some TS warning:

• Better typing for WeakMap
• TempNode constructor name is not set from existing children like AssignNode or SetNode so I set the name as optional
• String.charCodeAt requires an argument
• Other small fixes

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	339.2 79.01	339.2 79.01	+0 B +0 B
WebGPU	485.98 134.92	485.98 134.91	+6 B -5 B
WebGPU Nodes	485.44 134.82	485.45 134.81	+6 B -3 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	465.1 112.06	465.1 112.06	+0 B +0 B
WebGPU	555.38 150.4	555.38 150.39	+6 B -5 B
WebGPU Nodes	511.23 140.1	511.24 140.09	+6 B -4 B