feat(admin): apply design system to Orders list/detail/edit/table

- Add PageHeader + Operations eyebrow on list page
- Detail page: PageHeader with order-id/date eyebrow, customer title,
  total/status subtitle, AdminBadge tone for pickup + payment processor
- AdminOrdersPanel: KPIStat for stat cards, EmptyState with Create your
  first order CTA, AdminBadge tone for status pills, lucide-react icons,
  all hardcoded Tailwind colors replaced with var(--admin-*) tokens
- OrderTableBody: AdminBadge tone for status + pickup pills, all hardcoded
  colors replaced with tokens
- OrderEditForm: ha-field-label + ha-field-input / ha-field-textarea classes
  for form fields, ha-segment control for status buttons, semantic pickup
  toggle with primary/warning tokens, all hardcoded colors replaced

Behavior preserved end-to-end. Type-check clean.

src/app/admin/orders/page.tsx

@@ -65,11 +65,12 @@ export default async function AdminOrdersPage() {
   }
 
   return (
-    <div className="min-h-screen bg-[var(--admin-bg)]">
+    <div className="min-h-screen" style={{ backgroundColor: "var(--admin-bg)" }}>
       <div className="px-4 sm:px-6 md:px-8 pt-4 sm:pt-6">
+        <p className="ha-eyebrow mb-2">Operations</p>
         <PageHeader
           title="Orders"
-          subtitle="Manage customer orders and pickup status"
+          subtitle="View, filter, and manage customer orders."
           icon={
             <svg className="h-5 w-5 sm:h-6 sm:w-6" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
               <path d="M6 2 3 6v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2V6l-3-4Z"/>
@@ -82,7 +83,13 @@ export default async function AdminOrdersPage() {
 
       {/* Content */}
       <div className="px-4 sm:px-6 md:px-8 py-4 sm:py-6">
-        <div className="rounded-2xl border border-[var(--admin-border)] bg-white overflow-hidden">
+        <div
+          className="rounded-2xl border overflow-hidden"
+          style={{
+            borderColor: "var(--admin-border)",
+            backgroundColor: "var(--admin-card-bg)",
+          }}
+        >
           <AdminOrdersPanel
             initialOrders={brandOrders}
             initialStops={brandStops}