refactor: enforce global Button component usage across all files (Header, Forms, Grids, MDX)

Former-commit-id: aa55620667a28e5c00ab2603da6ea6dc1e1c5ecf

components/blocks/JobListingBlock.tsx

@@ -1,5 +1,6 @@
 import React from 'react';
 import Link from 'next/link';
+import { Button } from '@/components/ui/Button';
 
 export interface JobListingBlockProps {
   title?: string;
@@ -89,7 +90,9 @@ export const JobListingBlock = async (props: JobListingBlockProps) => {
             ) : (
               <div className="bg-neutral-50 border border-neutral-100 rounded-2xl p-12 text-center">
                 <p className="text-text-secondary text-lg">{emptyStateMessage}</p>
-                <Link href={emptyStateLinkHref} className="inline-block mt-6 text-primary font-bold hover:underline">{emptyStateLinkText}</Link>
+                <Button href={emptyStateLinkHref} variant="primary" className="mt-6">
+                  {emptyStateLinkText}
+                </Button>
               </div>
             )}
           </div>