ui-next: refactor plugin loader (#1190)

examples/plugins/ui-next-plugin/ui/pages/example_css.tsx

@@ -0,0 +1,12 @@
+import { Link } from '@hydrooj/ui-next';
+import styles from '../styles.module.css'; // (1) CSS module — scoped class names
+
+export default function ExampleCss() {
+    return (
+        <div className={styles.card}>
+            <span className={styles.badge}>CSS module</span>
+            <h2 className={styles.title}>Scoped class names</h2>
+            <p><Link to="example_home">← Back</Link></p>
+        </div>
+    );
+}