fix(config): remove "use client" directive to fix ui-core build

[halvaradop]

Description

This pull request removes the "use client" directive from the @halvaradop/ui-core package. Including this directive at the top level of the package was causing rendering issues in applications using Server Components—particularly in Next.js—because it forces the file to be treated as a Client Component, preventing its usage in server-rendered environments.

This issue was identified while integrating the library into a Next.js project, which distinguishes between client and server components using "use client" and "use server" directives.

By removing the directive, we restore compatibility with server-side rendering (SSR) and allow developers to apply "use client" only where needed in their own application code.

Checklist

• Added documentation.
• The changes do not generate any warnings.
• I have performed a self-review of my own code.
• All tests have been added and pass successfully.

Notes