Fix narrow PWA layout on tablet with standalone width rules.

Allow any orientation in manifest, widen content and enable dual-column mode in installed apps on tablet viewports, with iOS display-mode fallback.

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

components/pwa/pwa-display-mode.tsx

@@ -0,0 +1,19 @@
+"use client";
+
+import { useEffect } from "react";
+
+/** iOS / iPad PWA 部分版本不识别 display-mode 媒体查询，用 data 属性兜底 */
+export default function PwaDisplayMode() {
+  useEffect(() => {
+    const standalone =
+      window.matchMedia("(display-mode: standalone)").matches ||
+      (window.navigator as Navigator & { standalone?: boolean }).standalone ===
+        true;
+
+    if (standalone) {
+      document.documentElement.dataset.displayMode = "standalone";
+    }
+  }, []);
+
+  return null;
+}