Add proof of concept UI for ‘Add information’ feature on author page

This merge request introduces a proof of concept for adding new statements on the author page in Paulina.

What I did:

Added an “Add information” button positioned outside and below the biography table.

Implemented a dropdown showing only the missing fields.

When a field is selected, it displays the selected field label and input box just below the table, following the provided design sketch.

Reused Search UI styles for buttons, dropdown, and inputs for consistent look and feel.

No backend or Wikidata integration yet — this is strictly a UI-only proof of concept.

Implementation Notes

The layout respects existing spacing and accessibility standards.

Code structured for easy future integration with the Wikidata API.

Added inline comments for clarity and maintainability.

Next Steps

Connect the form to Wikidata API for saving statements.

Implement validation and user feedback states.

Add tests for dropdown and input interactions.