feat(PageCard): add `links` slot and props

[rasyidly]

🔗 Linked issue

❓ Type of change

• [ ] 📖 Documentation (updates to the documentation or readme)
• [ ] 🐞 Bug fix (a non-breaking change that fixes an issue)
• [x] 👌 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 PR adds a dedicated links slot and props to UPageCard, enabling users to place interactive controls (e.g., buttons, menus) alongside the title/leading area without mixing them into the default slot. This solves the common struggle when the default slot contains complex content like UTable or UForm, ensuring a clean, predictable layout. The links slot or props is rendered within the card’s wrapper area so actions align naturally with the header/body composition across orientations and variants.

Here the example usage:

• On default orientation (vertical)

<UPageCard title="Card Title" description="This is a description." icon="i-lucide-star" class="w-4xl">
  <template #links>
    <UButton label="Action 1" />
    <UButton label="Action 2" variant="soft" />
  </template>
  <Placeholder class="h-32" />
</UPageCard>

• On horizontal orientation

<UPageCard title="Card Title" description="This is a description." icon="i-lucide-star" orientation="horizontal" class="w-full" :links="[
  { label: 'Action 1' },
  { label: 'Action 2', variant: 'soft' }
  ]">
    <Placeholder class="h-32" />
</UPageCard>

Output:

📝 Checklist

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

[pkg-pr-new[bot]]

npm i https://pkg.pr.new/@nuxt/ui@5129

commit: 56806c8