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

components/Seo.tsx

@@ -0,0 +1,21 @@
+import React from 'react';
+import { Helmet } from 'react-helmet';
+
+interface SeoProps {
+  title: string;
+  description?: string;
+}
+
+const Seo: React.FC<SeoProps> = ({ title, description }) => {
+  const fullTitle = `${title} | ГеоВектор`;
+
+  return (
+    <Helmet>
+      <title>{fullTitle}</title>
+      {description && <meta name="description" content={description} />}
+    </Helmet>
+  );
+};
+
+export default Seo;
+