fix: regenerate FAQ editor keys on locale switch

- Locale switch now regenerates all stable keys so editors remount fresh
- Fixes same-length locale switch (e.g., ru 3 items → en 3 items) reusing wrong editors
- Move keyCounter increment out of functional updater for StrictMode purity
- Remove void locale — prop is now used for key regeneration

src/pages/AdminInfoPageEditor.tsx

@@ -540,7 +540,12 @@ function FaqBuilder({ items, onChange, locale, localeLabel }: FaqBuilderProps) {
   const keyCounter = useRef(0);
   const [itemKeys, setItemKeys] = useState<number[]>(() => items.map(() => keyCounter.current++));
 
-  // Sync key count when items change externally (e.g., locale switch resets items)
+  // Regenerate all keys on locale switch (items are semantically different)
+  useEffect(() => {
+    setItemKeys(items.map(() => keyCounter.current++));
+  }, [locale]); // eslint-disable-line react-hooks/exhaustive-deps
+
+  // Sync key count when items added/removed within the same locale
   useEffect(() => {
     setItemKeys((prev) => {
       if (prev.length === items.length) return prev;
@@ -580,7 +585,8 @@ function FaqBuilder({ items, onChange, locale, localeLabel }: FaqBuilderProps) {
   );
 
   const handleAdd = useCallback(() => {
-    setItemKeys((prev) => [...prev, keyCounter.current++]);
+    const newKey = keyCounter.current++;
+    setItemKeys((prev) => [...prev, newKey]);
     onChange([...items, { q: '', a: '' }]);
   }, [items, onChange]);
 
@@ -614,8 +620,6 @@ function FaqBuilder({ items, onChange, locale, localeLabel }: FaqBuilderProps) {
     [items, onChange],
   );
 
-  void locale;
-
   return (
     <div className="space-y-4">
       <div className="flex items-center justify-between">