收口移动端入口与文案（05-30-mobile-confirmed-entry-copy-followups）

client/src/pages/MobilePurchaseRequestsPage.tsx

@@ -193,8 +193,12 @@ export function MobilePurchaseRequestsPage() {
 
       <section className="mobile-card" data-testid="mobile-purchase-requests-list">
         <div className="mobile-command-surface mb-4">
+          <label className="text-xs font-medium text-zinc-500" htmlFor="mobile-purchase-current-search">
+            当前列表搜索
+          </label>
           <Input
-            aria-label="搜索采购"
+            id="mobile-purchase-current-search"
+            aria-label="当前列表搜索"
             value={searchInput}
             onChange={(event) => setSearchInput(event.target.value)}
             placeholder="搜索编号、标题、供应商"