feat(be+admin): 后台看板扩展 + 社区内容安全审核

看板（Recharts）:
- 概览页加 DAU/WAU/MAU、今日/本月新增 KPI，新增趋势/活跃趋势/月活/留存曲线
- GET /admin/analytics 内存计算，活跃口径=当天有记录/发帖/评论，排除 bot

内容安全（微信官方 UGC）:
- 文本 msg_sec_check 同步判、图片 media_check_async 异步查
- 帖子/评论加 pending/rejected 审核态，feed 只放 published
- 图片结果回调 /api/wx/sec-callback，JSON/XML + 明文模式，签名校验
- 检测不了/未发布时一律转待审核，走后台手动审核
- 后台帖子/评论审核页：修好看不到图（补 attachPostImages）、
  加状态筛选 + 通过/打回；新增评论审核状态接口

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

pets-be/web/admin/src/lib/api.ts

@@ -101,6 +101,7 @@ export const api = {
   logout: () => http.post('/admin/logout', { refresh_token: getRefreshToken() }),
   me: () => http.get<any, any>('/admin/me'),
   stats: () => http.get<any, { users: number; pets: number; posts: number; records: number }>('/admin/stats'),
+  analytics: (days = 30) => http.get<any, any>('/admin/analytics', { params: { days } }),
 
   users: (params: any) => http.get<any, Page<any>>('/admin/users', { params }),
   setUserDisabled: (id: number, disabled: boolean) =>
@@ -112,6 +113,7 @@ export const api = {
   setPostStatus: (id: number, status: string) => http.put(`/admin/posts/${id}/status`, { status }),
 
   comments: (params: any) => http.get<any, Page<any>>('/admin/comments', { params }),
+  setCommentStatus: (id: number, status: string) => http.put(`/admin/comments/${id}/status`, { status }),
   deleteComment: (id: number) => http.delete(`/admin/comments/${id}`),
 
   articles: (params: any) => http.get<any, Page<any>>('/admin/articles', { params }),