Add shared customer auth, cart handoff, and account dropdown.

Mirror Meshkee customer sessions onto the storefront, continue checkout on the customer dashboard, and show profile/orders/admin links under the header name.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/components/providers/AppProviders.tsx

@@ -0,0 +1,18 @@
+"use client";
+
+import { AuthProvider } from "@/lib/auth";
+import { CartProvider } from "@/lib/cart";
+
+export function AppProviders({
+  children,
+  businessId,
+}: {
+  children: React.ReactNode;
+  businessId: string;
+}) {
+  return (
+    <AuthProvider businessId={businessId}>
+      <CartProvider>{children}</CartProvider>
+    </AuthProvider>
+  );
+}