feat: add news section with admin editor and public article view

- NewsSection with animated grid background, category filters, featured cards
- AdminNews list page with toggle publish/featured, pagination
- AdminNewsCreate with TipTap rich text editor, URL validation
- NewsArticle detail page with DOMPurify sanitization, Telegram back button
- Toggle component with WCAG 44px touch targets, role=switch
- Prose styles for highlight marks and responsive iframes
- i18n translations (en, ru, zh, fa)

src/pages/Dashboard.tsx

@@ -10,6 +10,7 @@ import { balanceApi } from '../api/balance';
 import { wheelApi } from '../api/wheel';
 import Onboarding, { useOnboarding } from '../components/Onboarding';
 import PromoOffersSection from '../components/PromoOffersSection';
+import NewsSection from '../components/news/NewsSection';
 import SubscriptionCardActive from '../components/dashboard/SubscriptionCardActive';
 import SubscriptionCardExpired from '../components/dashboard/SubscriptionCardExpired';
 import TrialOfferCard from '../components/dashboard/TrialOfferCard';
@@ -335,6 +336,9 @@ export default function Dashboard() {
         </Link>
       )}
 
+      {/* News Section */}
+      <NewsSection />
+
       {/* Onboarding Tutorial */}
       {showOnboarding && (
         <Onboarding