fix: prevent unnecessary fetch when reaching the maximum page

[jacksonplus]

🔗 Linked issue

resolves #353

❓ 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

The page change handler prefetches page.value + 1 on each navigation, but it
does not check whether this next page exceeds maxPage. This causes the app to
fetch non-existent pages (e.g. page 11 when only 10 pages exist), resulting in
unnecessary network requests without any benefit.

This PR updates the logic to:

• Use the target page (to + 1) as the prefetch target instead of page.value + 1.
• Only prefetch when to + 1 <= maxPage.
• Ensure displayedPage is always updated, even on the last page.

This avoids invalid requests, improves runtime efficiency, and preserves the
intended UX behavior.