This alleviates type errors when there's a different version of reactive-element that @lit/localize is using versus what the user's component is using.

Because localized is a class decorator, the standard Interface with Omit or Pick was not usable as there were static properties on it that conflict. I tried Pick<typeof ReactiveElement, 'addInitializer'> but the initializer type references ReactiveElement directly which breaks because of renderRoot.

I also removed the dependency on @lit/reactive-element and just import everything from lit.

I do wonder though.. @lit/localize only uses the lit package for types/interfaces. It exports utilities strictly meant to be used with lit projects and nothing is standalone. This is a prime candidate for marking lit as a peer dependency as described in lit/rfcs#31.

I tried it locally by updating the package.json to specify lit as a peer dependency, without the loosened type fix npm pack and installed the tarball in a lit 2 test project that was having type errors before. It no longer errors as it did not create a nested duplicate @lit/reactive-element. But, to be fair, this was also the case with just expanding the dependency version to include lit 2 even as a non-peer regular dependency as npm was able to dedupe it then too.