feat: Linear-style UI redesign with improved mobile experience

Major changes:
- Redesign cabinet with Linear-style components and top navigation
- Replace detail modals with dedicated pages (users, broadcasts, email templates)
- Add email channel support for broadcasts
- Remove pull-to-refresh, improve drag-and-drop on touch devices
- Fix Telegram Mini App: fullscreen, back button, scroll restoration
- Unify admin pages color scheme to design system
- Mobile-first improvements: horizontal tabs for settings, better touch targets

src/components/layout/AppShell/MobileBottomNav.tsx

@@ -0,0 +1,78 @@
+import { Link, useLocation } from 'react-router-dom';
+import { useTranslation } from 'react-i18next';
+import { motion } from 'framer-motion';
+
+import { cn } from '@/lib/utils';
+import { usePlatform } from '@/platform';
+
+// Icons
+import { HomeIcon, SubscriptionIcon, WalletIcon, UsersIcon, ChatIcon } from './icons';
+
+interface MobileBottomNavProps {
+  isKeyboardOpen: boolean;
+  referralEnabled?: boolean;
+}
+
+export function MobileBottomNav({ isKeyboardOpen, referralEnabled }: MobileBottomNavProps) {
+  const { t } = useTranslation();
+  const location = useLocation();
+  const { haptic } = usePlatform();
+
+  const isActive = (path: string) => location.pathname === path;
+
+  // Core navigation items for bottom bar
+  const coreItems = [
+    { path: '/', label: t('nav.dashboard'), icon: HomeIcon },
+    { path: '/subscription', label: t('nav.subscription'), icon: SubscriptionIcon },
+    { path: '/balance', label: t('nav.balance'), icon: WalletIcon },
+    ...(referralEnabled ? [{ path: '/referral', label: t('nav.referral'), icon: UsersIcon }] : []),
+    { path: '/support', label: t('nav.support'), icon: ChatIcon },
+  ];
+
+  const handleNavClick = () => {
+    haptic.impact('light');
+  };
+
+  return (
+    <nav
+      className={cn(
+        'fixed z-50 transition-all duration-200 lg:hidden',
+        'bg-dark-900/95 backdrop-blur-linear',
+        'border border-dark-700/30',
+        isKeyboardOpen ? 'pointer-events-none opacity-0' : 'opacity-100',
+      )}
+      style={{
+        bottom: 'calc(16px + env(safe-area-inset-bottom, 0px))',
+        left: '16px',
+        right: '16px',
+        borderRadius: 'var(--bento-radius, 24px)',
+        padding: '8px 4px',
+        boxShadow: '0 4px 30px rgba(0, 0, 0, 0.4), 0 0 0 1px rgba(255, 255, 255, 0.05) inset',
+      }}
+    >
+      <div className="flex justify-around">
+        {coreItems.map((item) => (
+          <Link
+            key={item.path}
+            to={item.path}
+            onClick={handleNavClick}
+            className={cn(
+              'relative flex min-w-[56px] flex-1 shrink-0 flex-col items-center justify-center rounded-2xl px-3 py-2.5 transition-all duration-200',
+              isActive(item.path) ? 'text-accent-400' : 'text-dark-500 hover:text-dark-300',
+            )}
+          >
+            {isActive(item.path) && (
+              <motion.div
+                layoutId="bottom-nav-active"
+                className="absolute inset-0 rounded-2xl bg-accent-500/15"
+                transition={{ type: 'spring', stiffness: 500, damping: 30 }}
+              />
+            )}
+            <item.icon className="relative z-10 h-5 w-5" />
+            <span className="relative z-10 mt-1 whitespace-nowrap text-2xs">{item.label}</span>
+          </Link>
+        ))}
+      </div>
+    </nav>
+  );
+}