SW: Add secure headers and clean up

[LeviPesin]

Fixes #24212

Description

Add the required secure headers to the editor's service worker and clean up it.

@mattrossman Please confirm this works.

[mattrossman]

I'm testing it here: https://rawcdn.githack.com/LeviPesin/three.js-1/a0f8cbd345e98f3e9ecf3fc1bf922add84d98905/editor/index.html

It isn't working for me.

The FetchEvent for "https://rawcdn.githack.com/LeviPesin/three.js-1/a0f8cbd345e98f3e9ecf3fc1bf922add84d98905/editor/index.html" resulted in a network error response: a Response whose "body" is locked cannot be used to respond to a request.

The trace points to this line:

https://github.com/LeviPesin/three.js-1/blob/a0f8cbd345e98f3e9ecf3fc1bf922add84d98905/editor/sw.js#L257

Perhaps there is some additional code from coi-serviceworker that should be copied over.

[LeviPesin]

Should be fixed now.

[mattrossman]

Not seeing it on my end: https://rawcdn.githack.com/LeviPesin/three.js-1/9d87837f28a96116bea898506350269f2bf59a8c/editor/index.html

[LeviPesin]

It seems that unpkg does not provide CORP header, so we cannot use COEP: require-corp and should use the new COEP: credentialless.

[LeviPesin]

But it still does not work... I am unsure why.

[mattrossman]

In my case mattrossman@bc818a7 I had to copy the two libs (ffmpeg.wasm and es-module-shims) from unpkg locally. Working demo.

[LeviPesin]

I think @mrdoob should decide should we keep these libs locally, investigate ways to enable the SW to work with cross-origin requests, or just use a non-SharedArrayBuffer version.

[mrdoob]

Is the non-SharedArrayBuffer version 10x slower or something? 🤔

[LeviPesin]

I think it is exactly number-of-coresX slower, because SharedArrayBuffer allows multithreading. I think we can actually keep the libs like we do with the other libs?

[mrdoob]

Alright, lets host the libraries then 👍

[LeviPesin]

Done.

[LeviPesin]

Is there something preventing merging this PR?

[LeviPesin]

@mrdoob Can this PR be merged, please?

[LeviPesin]

@mrdoob @Mugen87 Something preventing the merge?

[mrdoob]

Sorry for the delay!

[mrdoob]

Thanks!