fix(ui): remove @tailwindcss/browser@4 to fix button visibility on settings page

The Remove from DB button (and other buttons) was invisible due to CSS
conflicts from loading both @tailwindcss/browser@4 and tailwindcss@2.2.19
simultaneously. The v4 browser script injected a Preflight reset that set
button { background-color: transparent; color: inherit; } and caused state
variants (hover:, focus:, disabled:) to generate empty CSS rules.

Removing the v4 CDN script leaves Tailwind v2 as the single source of
truth for utility classes, restoring correct button styling site-wide.

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

frontend/templates/base.html

@@ -5,7 +5,6 @@
     <title>{% block title %}DocuElevate{% endblock %}</title>
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <!-- Tailwind CSS or other global CSS references -->
-    <script src="https://cdn.jsdelivr.net/npm/@tailwindcss/browser@4"></script>
     <link rel="stylesheet" href="/static/styles.css" />
     <!-- Alpine.js moved to head for earlier loading -->
     <script src="https://cdn.jsdelivr.net/npm/alpinejs@3.x.x/dist/cdn.min.js" defer></script>