✨(front) add useIsMobile hook

This hook tells whether the current browser is a mobile one or not.

src/frontend/src/utils/useIsMobile.ts

@@ -0,0 +1,20 @@
+import { isMobileBrowser } from '@livekit/components-core'
+import { useEffect, useState } from 'react'
+
+export const useIsMobile = () => {
+  const [isMobile, setIsMobile] = useState(isMobileBrowser())
+
+  useEffect(() => {
+    const handleResize = () => {
+      setIsMobile(isMobileBrowser())
+    }
+
+    window.addEventListener('resize', handleResize)
+
+    return () => {
+      window.removeEventListener('resize', handleResize)
+    }
+  }, [])
+
+  return isMobile
+}