style: update surface colors and typography for improved contrast and readability across various components

- Changed text colors from surface-400 to surface-600 and surface-500 to surface-700 for better visibility in multiple Svelte files.
- Updated background and border colors in app.css for a more cohesive industrial design.
- Adjusted font weights and sizes for headings, labels, and buttons to enhance clarity and user experience.
- Refined styles for tables, badges, and buttons to align with the new design language.
- Added new styles for input fields and switches to maintain consistency in the UI.

hub/admin-web/src/lib/components/EmptyState.svelte

@@ -13,14 +13,14 @@
 </script>
 
 <div class="saas-empty">
-	<div class="mb-1 flex h-12 w-12 items-center justify-center rounded-2xl bg-surface-100 text-surface-400">
+	<div class="mb-1 flex h-12 w-12 items-center justify-center border border-surface-300 bg-surface-100 text-surface-600">
 		<svg class="h-6 w-6" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.75">
 			<path stroke-linecap="round" stroke-linejoin="round" d="M3.75 6.75h16.5M3.75 12h16.5m-16.5 5.25H12" />
 		</svg>
 	</div>
-	<p class="text-sm font-medium text-surface-700">{title}</p>
+	<p class="text-sm font-medium text-surface-900">{title}</p>
 	{#if description}
-		<p class="max-w-sm text-sm text-surface-400">{description}</p>
+		<p class="max-w-sm text-sm text-surface-600">{description}</p>
 	{/if}
 	{#if action}
 		<div class="mt-2">