feat: use Web Worker for OBJ loading to prevent UI blocking (#7846)

## Summary

- Replace OBJLoader with OBJLoader2Parallel from wwobjloader2
- OBJ parsing now runs in a Web Worker, keeping UI responsive
- Add 100MB file size limit with user-friendly error message

reduce loading time for 97M obj from 9s to 3s

fix https://github.com/Comfy-Org/ComfyUI_frontend/issues/7843

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7846-feat-use-Web-Worker-for-OBJ-loading-to-prevent-UI-blocking-2df6d73d36508140bea3c87e83d11278)
by [Unito](https://www.unito.io)

src/extensions/core/load3d/interfaces.ts

@@ -4,8 +4,8 @@ import { ViewHelper } from 'three/examples/jsm/helpers/ViewHelper'
 import { FBXLoader } from 'three/examples/jsm/loaders/FBXLoader'
 import { type GLTF, GLTFLoader } from 'three/examples/jsm/loaders/GLTFLoader'
 import { MTLLoader } from 'three/examples/jsm/loaders/MTLLoader'
-import { OBJLoader } from 'three/examples/jsm/loaders/OBJLoader'
 import { STLLoader } from 'three/examples/jsm/loaders/STLLoader'
+import { type OBJLoader2Parallel } from 'wwobjloader2'
 
 export type MaterialMode =
   | 'original'
@@ -179,7 +179,7 @@ export interface ModelManagerInterface {
 
 export interface LoaderManagerInterface {
   gltfLoader: GLTFLoader
-  objLoader: OBJLoader
+  objLoader: OBJLoader2Parallel
   mtlLoader: MTLLoader
   fbxLoader: FBXLoader
   stlLoader: STLLoader