perf(P22PROD1-1,P22PROD1-2): 路由懒加载与Vite分包消除大包warning

client/src/components/common/RoutePageFallback.tsx

@@ -0,0 +1,12 @@
+import { Spinner } from "../ui/spinner";
+
+export function RoutePageFallback() {
+  return (
+    <div className="flex min-h-[40vh] items-center justify-center">
+      <div className="card-std flex items-center gap-3 px-4 py-3 text-sm text-zinc-500">
+        <Spinner size="sm" />
+        <span>页面加载中...</span>
+      </div>
+    </div>
+  );
+}