maintenance: Move package.json to the repository root

[MH4GF]

Description

Move package.json to the repository root. And the associated files are adjusted accordingly.

Motivation

• Changeset does not work unless in repository root: Revert "Review changeset configuration to resolve errors in GitHub Actions" #257
  • It is better to have a changeset when receiving contributions from outside.
• Other developer tools are easier to handle in the repository root.

There may be a future when a backend directory is needed, but we can think about that at that time.

Blocking

After the merge of #349, merge this PR after the changeset is gone.

CI Errors

https://github.com/liam-hq/liam/actions/runs/12463106970/job/34784974243?pr=351

It seems that the summary generation fails due to large change differences.
Perhaps we can ignore it and merge it, and there will be no problem with the next PR.

[MH4GF]

@masutaka Please your review about CI Errors section!

[masutaka]

CI Errors

https://github.com/liam-hq/liam/actions/runs/12463106970/job/34784974243?pr=351

It seems that the summary generation fails due to large change differences.
Perhaps we can ignore it and merge it, and there will be no problem with the next PR.

You may be a little misguided in your perception. But if a vulnerable package is merged into the main branch, Dependabot alerts will find it. 😄

FYI:
Dependency review only looks at packages that have changed in the diff of a pull request, so the next pull request will not find any problems with this pull request.

[MH4GF]

@masutaka

You may be a little misguided in your perception. But if a vulnerable package is merged into the main branch, Dependabot alerts will find it. 😄

Oh... you are right. It already contained a vulnerable package.
We will be working on a dependency update within the next two weeks!

[masutaka]

FYI:

It seems that the summary generation fails due to large change differences.

I have subscribed to this issue!

• Job Summary Size Limitation aborts the job [BUG]  actions/dependency-review-action#786

[FunamaYukina]

I've tested the app and it's working fine. LGTM!✨

[MH4GF]

Thanks for review!
First, merge #349.