fix(unplugin): add declared types for #build/app.config

[danielroe]

🔗 Linked issue

❓ Type of change

• 📖 Documentation (updates to the documentation or readme)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

This resolves type checking issues associated with using #build/app.config in a Vue project. There are still additional type issues to resolve:

• #imports (useAppConfig)
• #vue-router (this is no longer needed - it can be vue-router)
• browser/dom which is probably a straightforward change to vue tsconfig

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

[pkg-pr-new]

pnpm add https://pkg.pr.new/@nuxt/ui@2625

commit: 8117059