refactor: comprehensive frontend review — consistency, a11y, code quality

- Replace event dispatchers with BookingContext (Hero, Header, FloatingContact)
- Add focus trap hook for modals (SignupModal, NewsModal)
- Extract shared components: CollapsibleSection, ConfirmDialog, PriceField, AdminSkeleton
- Add delete confirmation dialog to ArrayEditor
- Replace hardcoded colors (#050505, #0a0a0a, #c9a96e, #2ecc71) with theme tokens
- Add CSS variables --color-surface-deep/dark for consistent dark surfaces
- Improve contrast: muted text neutral-500 → neutral-400 in dark mode
- Fix modal z-index hierarchy (modals z-60, header z-50, floats z-40)
- Consolidate duplicate formatDate → shared formatting.ts
- Add useMemo to TeamProfile groupMap computation
- Fix typography: responsive price text in Pricing section
- Add ARIA labels/expanded to FAQ, OpenDay, ArrayEditor grip handles
- Hide number input spinners globally
- Reorder admin sidebar: Dashboard → SEO → Bookings → site section order
- Use shared PriceField in Open Day editor
- Fix schedule grid first time slot (09:00) clipped by container
- Fix pre-existing type errors (bookings, hero, db interfaces)

src/app/admin/layout.tsx

@@ -29,13 +29,14 @@ import {
 const NAV_ITEMS = [
   { href: "/admin", label: "Дашборд", icon: LayoutDashboard },
   { href: "/admin/meta", label: "SEO / Мета", icon: Globe },
+  { href: "/admin/bookings", label: "Записи", icon: ClipboardList },
+  // Sections follow user-side order: Hero → About → Classes → Team → OpenDay → Schedule → Pricing → MC → News → FAQ → Contact
   { href: "/admin/hero", label: "Главный экран", icon: Sparkles },
   { href: "/admin/about", label: "О студии", icon: FileText },
   { href: "/admin/classes", label: "Направления", icon: BookOpen },
   { href: "/admin/team", label: "Команда", icon: Users },
   { href: "/admin/open-day", label: "День открытых дверей", icon: DoorOpen },
   { href: "/admin/schedule", label: "Расписание", icon: Calendar },
-  { href: "/admin/bookings", label: "Записи", icon: ClipboardList },
   { href: "/admin/pricing", label: "Цены", icon: DollarSign },
   { href: "/admin/master-classes", label: "Мастер-классы", icon: Star },
   { href: "/admin/news", label: "Новости", icon: Newspaper },