#18736 Admin UI improvements for large file libraries — scroll & upload button placement

Hello,

I'm using WP File Download with a large number of categories and files and I'd like to suggest two UI improvements for the admin panel:

1. Categories sidebar: internal scrolling When there are many categories, the left sidebar grows indefinitely in height, pushing the page content down and making navigation awkward. The .scroller_wrapper_inner element seems designed to handle scrolling, but core.css sets max-height: unset which disables it. A fixed height with overflow-y: auto on the sidebar (or a sticky/fixed position behavior) would make it much easier to navigate large category trees without losing context.

2. Upload buttons always visible at the top The file upload is positioned at the bottom of the file list. In a folder with many files, users must scroll to the bottom to upload — which is counterintuitive. Placing the upload controls (drag & drop area, "Add file", "Add remote file" buttons) above the file list, or as a sticky toolbar at the top of #pwrapper, would significantly improve the workflow.

Both issues become significant pain points for the use experience.

Thank you for considering these suggestions.