feat: simplify navigation and add RU/EN home and contacts

- simplify main navigation and hide extra menu items
- make home page more sales-focused with updated hero, benefits and fleet teaser
- add RU/EN handling for home and contacts, including SEO defaults
- integrate basic Strapi homepage API client (no breaking changes)
- update contacts page with messenger buttons and dynamic footer year

Made-with: Cursor

package.json

@@ -13,6 +13,7 @@
     "lucide-react": "^0.555.0",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",
+    "react-helmet": "^6.1.0",
     "react-router": "^6.22.3",
     "react-router-dom": "^6.22.3"
   },