Add Russian i18n with DB translations, locale API, and curator review UI.

UI chrome via react-i18next, catalog text in entity_translations with ru.wikipedia seeding, locale-aware search, and Translations page for publish workflow.

Co-authored-by: Cursor <cursoragent@cursor.com>

client/src/components/CatalogSearchBar.tsx

@@ -1,4 +1,5 @@
 import { useCallback, useEffect, useId, useMemo, useRef, useState } from 'react';
+import { useTranslation } from 'react-i18next';
 import type { CatalogSearchResult } from '../types';
 import { api, imageUrl, portraitThumbUrl } from '../api/client';
 import './CatalogSearchBar.css';
@@ -10,11 +11,6 @@ interface Props {
 }
 
 const TYPE_ORDER: CatalogSearchResult['type'][] = ['artist', 'movement', 'painting'];
-const TYPE_LABELS: Record<CatalogSearchResult['type'], string> = {
-  artist: 'Artists',
-  movement: 'Movements',
-  painting: 'Paintings',
-};
 
 function resultKey(item: CatalogSearchResult): string {
   return `${item.type}-${item.id}`;
@@ -30,6 +26,12 @@ export default function CatalogSearchBar({
   onSelectMovement,
   onSelectPainting,
 }: Props) {
+  const { t } = useTranslation('search');
+  const typeLabels: Record<CatalogSearchResult['type'], string> = {
+    artist: t('groupArtist'),
+    movement: t('groupMovement'),
+    painting: t('groupPainting'),
+  };
   const listboxId = useId();
   const rootRef = useRef<HTMLDivElement>(null);
   const inputRef = useRef<HTMLInputElement>(null);
@@ -91,7 +93,7 @@ export default function CatalogSearchBar({
         .catch(() => {
           if (cancelled) return;
           setResults([]);
-          setError('Search failed.');
+          setError(t('searchFailed'));
           setOpen(true);
           setActiveIndex(-1);
         })
@@ -141,7 +143,7 @@ export default function CatalogSearchBar({
   return (
     <div className="catalog-search" ref={rootRef}>
       <label className="catalog-search-label" htmlFor={`${listboxId}-input`}>
-        Search
+        {t('label')}
       </label>
       <div className="catalog-search-field">
         <input
@@ -156,7 +158,7 @@ export default function CatalogSearchBar({
           aria-activedescendant={
             showPanel && activeIndex >= 0 ? `${listboxId}-opt-${activeIndex}` : undefined
           }
-          placeholder="Search artists, paintings, movements…"
+          placeholder={t('placeholder')}
           value={query}
           autoComplete="off"
           spellCheck={false}
@@ -177,15 +179,15 @@ export default function CatalogSearchBar({
           id={`${listboxId}-listbox`}
           className="catalog-search-panel"
           role="listbox"
-          aria-label="Search results"
+          aria-label={t('resultsLabel')}
         >
           {error && <p className="catalog-search-message catalog-search-error">{error}</p>}
           {!error && !loading && flatResults.length === 0 && (
-            <p className="catalog-search-message">No matches found.</p>
+            <p className="catalog-search-message">{t('noMatches')}</p>
           )}
           {grouped.map((group) => (
             <div key={group.type} className="catalog-search-group">
-              <p className="catalog-search-group-label">{TYPE_LABELS[group.type]}</p>
+              <p className="catalog-search-group-label">{typeLabels[group.type]}</p>
               <ul className="catalog-search-list">
                 {group.items.map((item) => {
                   const flatIndex = flatResults.findIndex((r) => resultKey(r) === resultKey(item));