refactor: repartition server-side and client-side code

app/.client/hooks/useViewport.ts

@@ -0,0 +1,18 @@
+import { useEffect, useState } from 'react';
+
+const useViewport = (threshold = 1024) => {
+  const [isSmallViewport, setIsSmallViewport] = useState(window.innerWidth < threshold);
+
+  useEffect(() => {
+    const handleResize = () => setIsSmallViewport(window.innerWidth < threshold);
+    window.addEventListener('resize', handleResize);
+
+    return () => {
+      window.removeEventListener('resize', handleResize);
+    };
+  }, [threshold]);
+
+  return isSmallViewport;
+};
+
+export default useViewport;