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/components/ui/SignupModal.tsx

@@ -4,6 +4,7 @@ import { useState, useEffect, useCallback } from "react";
 import { createPortal } from "react-dom";
 import { X, CheckCircle, Send, Phone as PhoneIcon, Instagram } from "lucide-react";
 import { BRAND } from "@/lib/constants";
+import { useFocusTrap } from "@/hooks/useFocusTrap";
 
 interface SignupModalProps {
   open: boolean;
@@ -47,6 +48,7 @@ export function SignupModal({
   const [error, setError] = useState("");
   const [success, setSuccess] = useState(false);
   const [successData, setSuccessData] = useState<Record<string, unknown> | null>(null);
+  const focusTrapRef = useFocusTrap<HTMLDivElement>(open);
 
   function handlePhoneChange(raw: string) {
     let digits = raw.replace(/\D/g, "");
@@ -141,10 +143,11 @@ export function SignupModal({
   if (!open) return null;
 
   return createPortal(
-    <div className="modal-overlay fixed inset-0 z-50 flex items-center justify-center p-4" role="dialog" aria-modal="true" aria-label={title} onClick={handleClose}>
+    <div className="modal-overlay fixed inset-0 z-[60] flex items-center justify-center p-4" role="dialog" aria-modal="true" aria-label={title} onClick={handleClose}>
       <div className="absolute inset-0 bg-black/70 backdrop-blur-sm" />
       <div
-        className="modal-content relative w-full max-w-md rounded-2xl border border-white/[0.08] bg-[#0a0a0a] p-6 sm:p-8 shadow-2xl"
+        ref={focusTrapRef}
+        className="modal-content relative w-full max-w-md rounded-2xl border border-white/[0.08] bg-neutral-950 p-6 sm:p-8 shadow-2xl"
         onClick={(e) => e.stopPropagation()}
       >
         <button