fix: support TypeScript 7 under npm alias

[jasonlyu123]

#3063 This PR adds a version check in bin/svelte-check before importing the main entry point. This way, we can throw an error about TypeScript 7 without having to remove all the top-level ts import just yet.

This also allows loading TypeScript 7 through an npm alias. i.e. install TypeScript 7 as "typescript-7": "npm:typescript@rc". This is mostly preparing for TypeScript 7 stable. According to the TypeScript RC announcement, once the stable version is released, the nightly version will also be released under "typescript" instead of "@typescript/native-preview".

I was originally considering moving all top-level imports to a few dynamic imports. And we try to load TypeScript 6 from @typescript/typescript-6. But even if we do that, people might still run into issues with svelte-kit sync and typescript-eslint

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🦋 Changeset detected

Latest commit: 51114db

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
svelte-check	Patch
svelte2tsx	Patch

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[dummdidumm]

Some stylistic comments otherwise looks good - now that TS7 is out and we know that they will not release it under the preview anymore is there anything we need to adjust in this PR?

[Suya1671]

It seems the typescript devs want the reverse to happen, since the put typescript 6 under a namespace. Maybe the repo should move to instead?

[jasonlyu123]

now that TS7 is out and we know that they will not release it under the preview anymore is there anything we need to adjust in this PR?

Just checked it again. I think that is all I can think of right now. We prioritise typescript-7 over @typescript/native-preview. And the one error message that mentioned @typescript/native-preview is checking for 7.0 nightly; people using 7.1 won't see it.

[jasonlyu123]

It seems the typescript devs want the reverse to happen, since the put typescript 6 under a namespace. Maybe the repo should move to instead?

It's explained here.

I was originally considering moving all top-level imports to a few dynamic imports. And we try to load TypeScript 6 from @typescript/typescript-6. But even if we do that, people might still run into issues with svelte-kit sync and typescript-eslint

[jasonlyu123]

Seems like they updated the blog to replace the typescript-7 alias with @typescript/native. It's because npm prioritises "typescript" over "typescript-7" when resolving the bin name conflict. I'll change it to that as well.