chore(admin-ui): orders index uses page header

resources/views/admin/orders/index.blade.php

@@ -8,6 +8,22 @@
     $exportQuery = http_build_query(array_filter($filters, fn ($value) => $value !== null && $value !== ''));
 @endphp
 
+<div class="page-header mb-20" data-page="admin.orders.index">
+    <div class="page-header-main">
+        <div>
+            <div class="page-header-title">订单监控</div>
+            <div class="page-header-subtitle">总台视角全局订单监控与运营看板（导出/筛选/趋势/关注项）。</div>
+        </div>
+        <div class="page-header-actions">
+            <a class="btn btn-secondary btn-sm" href="{{ '/admin/orders/export' . ($exportQuery ? ('?' . $exportQuery) : '') }}">导出 CSV</a>
+        </div>
+    </div>
+    <div class="page-header-meta">
+        <div>缓存：{{ $cacheMeta['store'] }} / TTL {{ $cacheMeta['ttl'] }}</div>
+        <div>提示：筛选条件支持时间范围与金额区间</div>
+    </div>
+</div>
+
 <details class="card mb-20 collapsible filters-card" data-role="collapsible" data-storage-key="admin.orders.filters" open>
     <summary class="collapsible-summary filters-summary">
         <div class="flex-between items-center">