Unify entities navigation, redesign time clock, and add invoice PDF preview.

Combine clients and businesses under entities, polish the web time clock,
and show live invoice PDF preview with tighter line-item editing.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/app/dashboard/businesses/[id]/page.tsx

@@ -50,7 +50,7 @@ export default async function BusinessDetailPage({
         variant="gradient"
       >
         <Button asChild variant="outline" className="shadow-sm">
-          <Link href="/dashboard/businesses">
+          <Link href="/dashboard/entities?tab=businesses">
             <ArrowLeft className="mr-2 h-4 w-4" />
             <span>Back to Businesses</span>
           </Link>