🩹(frontend) preload notifications translations to prevent flickering

The notifications namespace was being lazy-loaded when the first notification
appeared, causing a screen flicker during translation loading. Now preloading
the namespace during i18n initialization to ensure smooth rendering.

src/frontend/src/features/notifications/MainNotificationToast.tsx

@@ -12,6 +12,7 @@ import {
   ANIMATION_DURATION,
   ReactionPortals,
 } from '@/features/rooms/livekit/components/ReactionPortal'
+import { useTranslation } from 'react-i18next'
 
 export const MainNotificationToast = () => {
   const room = useRoomContext()
@@ -186,6 +187,10 @@ export const MainNotificationToast = () => {
     }
   }, [room])
 
+  // Without this line, when the component first renders,
+  // the 'notifications' namespace might not be loaded yet
+  useTranslation(['notifications'])
+
   return (
     <Div position="absolute" bottom={0} right={5} zIndex={1000}>
       <ToastProvider />