Load page.json by import, publish via fs, drop cookie auth

The editor no longer round-trips through /api/pages. Each route's
editor/page.tsx imports its own `../page.json` and hands it to
PageEditor as a prop, so the editor opens with the page already in
hand — no fetch, no loading state, no undo history seeded from a
placeholder. Globals still come from app.globals.json.

Publishing moves from `PUT /api/pages` to a `publishPage` server
action that writes the route's page.json with node:fs directly.
The target path is still built from the lib/pages.ts registry rather
than from the caller, so an unknown route key is rejected instead of
escaping app/.

Removes the customer account auth entirely: the httpOnly cookie
session, the /api/account/* handlers, the customer service and
GraphQL documents, the account-* blocks, and the /account/* routes.
The template has no auth, so nothing reads a cookie now.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01STGDvL4X7FhHHnxdRE2ayo

components/shopify/header.tsx

@@ -5,7 +5,6 @@ import Link from 'next/link';
 import { useCartStore } from '@/hooks/use-shopify-cart';
 import CartDrawer from '@/components/shopify/cart-drawer';
 import SearchDialog from '@/components/shopify/search-dialog';
-import AccountMenu from '@/components/shopify/account-menu';
 import ShopMenu from '@/components/shopify/shop-menu';
 import { RiShoppingBagLine, RiCloseLine, RiMenu3Line } from '@remixicon/react';
 import { Button } from '@/components/ui/button';
@@ -117,7 +116,6 @@ const Header: React.FC<HeaderProps> = ({
           {/* Actions */}
           <div className="flex items-center">
             <SearchDialog />
-            <AccountMenu />
             <CartIcon />
 
             {/* Mobile hamburger */}