修复发帖长文布局与手机下拉刷新，发版后自动重载失效 chunk，并整理站务文案。

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

frontend/src/components/AppRouteError.tsx

@@ -0,0 +1,60 @@
+import { useEffect } from 'react';
+import { isRouteErrorResponse, useRouteError } from 'react-router-dom';
+import { Button } from '@/components/ui/button';
+import { isChunkLoadError, reloadForStaleChunk } from '../utils/chunkLoad';
+
+function errorMessage(error: unknown): string {
+  if (isRouteErrorResponse(error)) {
+    if (typeof error.data === 'string' && error.data) return error.data;
+    if (error.data && typeof error.data === 'object' && 'message' in error.data) {
+      const m = (error.data as { message?: unknown }).message;
+      if (typeof m === 'string' && m) return m;
+    }
+    return error.statusText || `错误 ${error.status}`;
+  }
+  if (error instanceof Error) return error.message;
+  return String(error ?? '未知错误');
+}
+
+/**
+ * React Router 路由级错误页。
+ * 发版后动态模块 404 时自动刷新；其它错误给出手动刷新入口。
+ */
+export default function AppRouteError() {
+  const error = useRouteError();
+  const chunkMiss = isChunkLoadError(error);
+
+  useEffect(() => {
+    if (chunkMiss) reloadForStaleChunk();
+  }, [chunkMiss]);
+
+  if (chunkMiss) {
+    return (
+      <div className="error-page-shell">
+        <div className="error-page">
+          <div className="error-page__code" aria-hidden>…</div>
+          <h1 className="error-page__title">正在更新页面</h1>
+          <p className="error-page__desc">检测到程序已更新，正在自动刷新以加载最新版本…</p>
+        </div>
+      </div>
+    );
+  }
+
+  return (
+    <div className="error-page-shell">
+      <div className="error-page">
+        <div className="error-page__code" aria-hidden>500</div>
+        <h1 className="error-page__title">页面加载出错</h1>
+        <p className="error-page__desc">{errorMessage(error)}</p>
+        <div className="error-page__actions">
+          <Button size="sm" onClick={() => window.location.reload()}>
+            刷新页面
+          </Button>
+          <Button size="sm" variant="outline" onClick={() => { window.location.href = '/'; }}>
+            返回首页
+          </Button>
+        </div>
+      </div>
+    </div>
+  );
+}