feat(theme-4): sync inbox/announcements/presence/deposit from main

apps/admin/src/utils/html.ts

@@ -0,0 +1,12 @@
+/** 去除 HTML 标签，用于列表摘要与跑马灯纯文本 */
+export function stripHtml(html: string): string {
+  if (!html) return '';
+  if (!/[<>]/.test(html)) return html.trim();
+  const doc = new DOMParser().parseFromString(html, 'text/html');
+  return (doc.body.textContent ?? '').replace(/\s+/g, ' ').trim();
+}
+
+/** 判断富文本是否实质为空 */
+export function isHtmlEmpty(html: string): boolean {
+  return !stripHtml(html);
+}