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/app.html

@@ -12,6 +12,12 @@
 			href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&family=Noto+Sans+SC:wght@400;500;600;700&display=swap"
 			rel="stylesheet"
 		/>
+		<style>
+			/* Fallback before CSS bundle: CJK-first industrial base */
+			html {
+				font-family: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', 'Inter', sans-serif;
+			}
+		</style>
 		<title>CPH Admin</title>
 		%sveltekit.head%
 	</head>