Add news feature with CRUD operations and real-time notifications

- Implemented news management functionality, allowing admins to create, read, update, and delete news posts.
- Introduced a new SignalR event for broadcasting news updates to all connected clients.
- Updated API documentation to include new endpoints for news management.
- Enhanced frontend with a dedicated news page and admin interface for managing news posts.
- Added necessary localization for news-related terms in both Russian and English.

frontend/src/routes/__root.tsx

@@ -47,6 +47,9 @@ function RootLayout() {
       <Link to="/instructions" className="text-muted-foreground hover:text-foreground">
         {t('nav.instructions')}
       </Link>
+      <Link to="/news" className="text-muted-foreground hover:text-foreground">
+        {t('nav.news')}
+      </Link>
       <Link to="/settings" className="text-muted-foreground hover:text-foreground">
         {t('nav.settings')}
       </Link>