Enhance root layout and admin interface for better usability

- Updated the root layout to include a mobile menu toggle, improving navigation on smaller screens.
- Refactored navigation links and language/theme selection for better organization and accessibility.
- Added overflow handling for admin navigation and tables to ensure proper display on smaller screens.
- Improved translations for menu toggle accessibility in both Russian and English.

frontend/src/routes/admin.tsx

@@ -24,13 +24,13 @@ function AdminLayout() {
   return (
     <div className="mx-auto flex w-full max-w-5xl flex-col gap-6 px-6 py-10">
       <h1 className="text-2xl font-semibold tracking-tight">{t('nav.admin')}</h1>
-      <nav className="flex gap-1 border-b border-border">
+      <nav className="flex gap-1 overflow-x-auto border-b border-border">
         {TABS.map((tab) => (
           <Link
             key={tab.to}
             to={tab.to}
             activeOptions={{ exact: tab.to === '/admin' }}
-            className={cn('px-3 py-2 text-sm text-muted-foreground hover:text-foreground')}
+            className={cn('shrink-0 whitespace-nowrap px-3 py-2 text-sm text-muted-foreground hover:text-foreground')}
             activeProps={{ className: 'border-b-2 border-primary text-foreground font-medium' }}
           >
             {t(`admin.tabs.${tab.key}`)}