Verification Steps
Save the two files.
If your Chrome instance displayed the SwiftShader deprecation warning, add the
flag --enable-unsafe-swiftshader to your Chrome startup command if needed.
Reload https://localhost:3000/ or [https://10.0.3.246:3000/](https://10.0.3.246
:3000/).
Check the browser DevTools console: both previous errors (ChunkRenderer is not
defined and worker_threads externalized) will be gone, and you will
see:[Worker] Loaded
[Worker] Received message: { type: 'init', ... }
[Worker] Entering main loop

Click "Send Edit via Ring Buffer".
The console will report the edit pushed, the worker will generate the 36
vertices without blocking the main thread, and a green 3D cube will appear in
the viewport. You can drag with your mouse/touch to orbit and verify the
render.