第五轮深度测试：管理员撤回、所有人@提醒、失效附件UI，并核对现存后端问题清单

- messages-view.jsx: 拖拽发送/回复菜单在编辑态下的旁路修复；群主/管理员可撤回他人消息
  (对齐后端 authorizeIMMessageMutation 的 allowAdmin)；新增"所有人"@提醒(head.mention_all)。
- chat-message.jsx: system_action 头类型消息按 system_notice 同款渲染(此前显示"内容无效")。
- content-library-view.jsx: 语音/链接/图文收藏与聊天记录卡片补上 removed(已失效)态UI，
  之前只有 FileCard 处理了这个状态。
- call-panel.jsx: handleVideoOfferMsg(5步.then链，用reject sentinel跳过后续步骤)、
  handleToggleSpeakerClick 补组件卸载守卫，修完此前遗漏的两处。
- group-management-view.jsx: 治理开关(Governance.setField)和群主转让(OwnerSelect)
  补上乐观锁 version 参数(此前从不传，服务端 version<=0 时会跳过冲突检测)；群文件搜索框
  文案承诺"搜索文件名或者上传者"但服务端q参数只匹配文件名，改为拉取全量列表本地按文件名+
  已解析的上传者昵称一起过滤；群公告详情页补上从未被调用过的已读上报(readGroupAnnouncement)。

以上均用真实账号在浏览器/直接请求验证：管理员撤回、system_action渲染、mention_all、
文件按上传者搜索、公告已读上报(200)、治理开关stale-version探测确认409冲突检测生效。

7个并行测试agent对全部11章做了第二轮回归+现存后端问题清单逐条复核，结论待整理进
docs/IM-后端问题清单*.md（全部现存条目复核后均建议保留，多条证据强度从推断升级为已验证）。

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

umd/src_views_messages-view_jsx.dev.js

@@ -205,6 +205,7 @@ function isPeerRestricted(acs) {
   }
   return false;
 }
+const MENTION_ALL_UID = '__mention_all__';
 function shouldPresentCallPanel(callState) {
   return callState == _constants_js__WEBPACK_IMPORTED_MODULE_16__.CALL_STATE_OUTGOING_INITATED || callState == _constants_js__WEBPACK_IMPORTED_MODULE_16__.CALL_STATE_IN_PROGRESS;
 }
@@ -216,6 +217,7 @@ class MessagesView extends (react__WEBPACK_IMPORTED_MODULE_0___default().Compone
     this.state.toast = null;
     this.state.riskDialog = null;
     this.mentionedUsers = [];
+    this.mentionAllPending = false;
     this.componentSetup = this.componentSetup.bind(this);
     this.leave = this.leave.bind(this);
     this.sendMessage = this.sendMessage.bind(this);
@@ -389,6 +391,7 @@ class MessagesView extends (react__WEBPACK_IMPORTED_MODULE_0___default().Compone
         topic.onAuxUpdated = this.handleAuxUpdate;
       }
       this.mentionedUsers = [];
+      this.mentionAllPending = false;
       this.loadRelationshipContext(topic);
       this.loadGroupContext(topic);
       this.loadDraft(topic);
@@ -1022,7 +1025,8 @@ class MessagesView extends (react__WEBPACK_IMPORTED_MODULE_0___default().Compone
       }
       menuItems.push('menu_item_copy', 'menu_item_favorite');
       const recallWindow = this.state.messagePolicy ? this.state.messagePolicy.recall_window_seconds : 0;
-      if (params.userFrom == this.props.myUserId && params.seq > 0 && recallWindow > 0 && params.timestamp && params.timestamp.getTime() > new Date().getTime() - recallWindow * 1000) {
+      const canRecallAsAdmin = topic.isGroupType() && topic.getAccessMode() && topic.getAccessMode().isAdmin();
+      if ((params.userFrom == this.props.myUserId || canRecallAsAdmin) && params.seq > 0 && recallWindow > 0 && params.timestamp && params.timestamp.getTime() > new Date().getTime() - recallWindow * 1000) {
         menuItems.push('menu_item_recall');
       }
       if (topic.isSelfType()) {
@@ -1110,9 +1114,23 @@ class MessagesView extends (react__WEBPACK_IMPORTED_MODULE_0___default().Compone
     return (0,_lib_im_api_js__WEBPACK_IMPORTED_MODULE_19__.getGroupMembers)(this.state.topic, {
       mentionable: true,
       query
-    }).then(data => data.items || []);
+    }).then(data => {
+      const items = data.items || [];
+      const canMentionAll = !!(data.permissions && data.permissions.can_mention_all);
+      if (canMentionAll && '所有人'.includes((query || '').trim())) {
+        return [{
+          user_id: MENTION_ALL_UID,
+          display_name: '所有人'
+        }, ...items];
+      }
+      return items;
+    });
   }
   mentionSelected(uid, name) {
+    if (uid === MENTION_ALL_UID) {
+      this.mentionAllPending = true;
+      return;
+    }
     this.mentionedUsers = (this.mentionedUsers || []).filter(m => m.name !== name);
     this.mentionedUsers.push({
       uid,
@@ -1297,6 +1315,13 @@ class MessagesView extends (react__WEBPACK_IMPORTED_MODULE_0___default().Compone
       msg = parsed;
     }
     this.mentionedUsers = [];
+    if (this.mentionAllPending) {
+      head = {
+        ...(head || {}),
+        mention_all: true
+      };
+      this.mentionAllPending = false;
+    }
     if (typeHint) {
       head = {
         ...(head || {}),
@@ -2741,7 +2766,7 @@ class BaseChatMessage extends (react__WEBPACK_IMPORTED_MODULE_0___default().Pure
     let textSizeClass = 'message-content';
     const fullDisplay = this.props.isGroup && this.props.response && (this.props.sequence == 'single' || this.props.sequence == 'last');
     let content = this.props.content;
-    if (this.props.head && this.props.head['x-im-type'] === 'system_notice' && content && typeof content == 'object' && typeof content.text == 'string') {
+    if (this.props.head && (this.props.head['x-im-type'] === 'system_notice' || this.props.head['x-im-type'] === 'system_action') && content && typeof content == 'object' && typeof content.text == 'string') {
       content = content.text;
     }
     let bundleCard = null;