修复群邀请消息卡片丢弃"立即加入"按钮，被邀请人无法接受邀请

根因：POST /groups/{topic}/invitations 邀请成功后，后端会往邀请人与被邀请人的
单聊会话里发一条 x-im-type=system_action、template=group_invitation_created 的
消息，content.actions 里带着真实可用的 {type:"group_invitation_accept",
label:"立即加入", target_id:<invitation_id>}（对照参考图 6.3 加入群聊.png）。但
chat-message.jsx 原来对所有 system_action/system_notice 消息一律只取
content.text 渲染成纯文本，这个 action 数据被整体丢弃，消息只显示"邀请你加入群聊。"
没有任何按钮——im-api.js 里封装好的 acceptGroupInvitation() 因此从来没有调用点。

怎么修：chat-message.jsx 在原有的文本兜底之前，单独识别 content.actions 里
type=="group_invitation_accept" 的这一种模板，渲染一张带按钮的小卡片（其余
system_action/system_notice 模板的纯文本渲染保持不变，不受影响）；
messages-view.jsx 新增 handleAcceptGroupInvitation，调用 acceptGroupInvitation()
并用已有的 showToast 反馈结果，逐层传给 ChatMessage 的新 onAcceptGroupInvitation
prop。按钮点击后按 busy/joined/pending_approval/error 四态展示，避免重复提交。

验证：用两个真实账号（A 建群，直接对 B 发起 POST /invitations）复现，重新构建后
B 的会话里正确出现"邀请你加入群聊。"+"立即加入"按钮；点击后正确调用
POST /group-invitations/{id}/accept 并把返回的失败原因("服务器繁忙，请稍后重试")
展示出来——这一步暴露了一个独立的后端 500 bug（accept 接口本身的实现有问题，
已记录在测试报告里，不在本次前端修复范围内），前端的请求发起、按钮状态机和错误展示
均已确认按预期工作。

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

umd/src_views_messages-view_jsx.dev.js

@@ -248,6 +248,7 @@ class MessagesView extends (react__WEBPACK_IMPORTED_MODULE_0___default().Compone
     this.handleShowAnnouncement = this.handleShowAnnouncement.bind(this);
     this.handleShowJoinRequests = this.handleShowJoinRequests.bind(this);
     this.handleSendFriendVerification = this.handleSendFriendVerification.bind(this);
+    this.handleAcceptGroupInvitation = this.handleAcceptGroupInvitation.bind(this);
     this.handleBatchDelete = this.handleBatchDelete.bind(this);
     this.handleBatchFavorite = this.handleBatchFavorite.bind(this);
     this.handleAttachFile = this.handleAttachFile.bind(this);
@@ -1218,6 +1219,21 @@ class MessagesView extends (react__WEBPACK_IMPORTED_MODULE_0___default().Compone
     e.preventDefault();
     _lib_navigation_js__WEBPACK_IMPORTED_MODULE_20__["default"].navigateTo(_lib_navigation_js__WEBPACK_IMPORTED_MODULE_20__["default"].addUrlParam(_lib_navigation_js__WEBPACK_IMPORTED_MODULE_20__["default"].setUrlSidePanel('', 'friend-verification'), 'uid', this.state.topic));
   }
+  handleAcceptGroupInvitation(invitationId) {
+    return (0,_lib_im_api_js__WEBPACK_IMPORTED_MODULE_19__.acceptGroupInvitation)(invitationId).then(result => {
+      if (result && result.status == 'joined') {
+        this.showToast('已加入群聊');
+      } else if (result && result.status == 'pending_approval') {
+        this.showToast('申请已提交，等待管理员通过');
+      } else {
+        this.showToast('已处理该邀请');
+      }
+      return result;
+    }).catch(err => {
+      this.showToast(err.message || '加入群聊失败，请重试');
+      throw err;
+    });
+  }
   showToast(text) {
     this.setState({
       toast: text
@@ -2055,6 +2071,7 @@ class MessagesView extends (react__WEBPACK_IMPORTED_MODULE_0___default().Compone
               userIsAdmin: this.state.isAdmin,
               relationship: this.state.relationshipContext ? this.state.relationshipContext.relationship : null,
               onSendFriendVerification: this.handleSendFriendVerification,
+              onAcceptGroupInvitation: this.handleAcceptGroupInvitation,
               selectMode: this.props.selectMode,
               selected: this.props.selectedSeqs && this.props.selectedSeqs.includes(msg.seq),
               onToggleSelect: this.props.onToggleMessageSelect,
@@ -2595,7 +2612,10 @@ class BaseChatMessage extends (react__WEBPACK_IMPORTED_MODULE_0___default().Pure
     super(props);
     this.state = {
       progress: 0,
-      voicePlayed: isVoicePlayed(props.tinode.getCurrentUserID(), props.topic, props.seq)
+      voicePlayed: isVoicePlayed(props.tinode.getCurrentUserID(), props.topic, props.seq),
+      invitationBusy: false,
+      invitationResult: null,
+      invitationError: null
     };
     if (props.uploader) {
       props.uploader.onProgress = this.handleProgress.bind(this);
@@ -2608,6 +2628,7 @@ class BaseChatMessage extends (react__WEBPACK_IMPORTED_MODULE_0___default().Pure
     this.handleCancelUpload = this.handleCancelUpload.bind(this);
     this.handleDraftyClick = this.handleDraftyClick.bind(this);
     this.handleVoicePlayed = this.handleVoicePlayed.bind(this);
+    this.handleAcceptGroupInvitation = this.handleAcceptGroupInvitation.bind(this);
     this.formatterContext = {
       formatMessage: props.intl.formatMessage.bind(props.intl),
       viewportWidth: props.viewportWidth,
@@ -2763,6 +2784,53 @@ class BaseChatMessage extends (react__WEBPACK_IMPORTED_MODULE_0___default().Pure
       this.props.onQuoteClick(replyToSeq);
     }
   }
+  handleAcceptGroupInvitation(invitationId) {
+    if (this.state.invitationBusy || this.state.invitationResult || !this.props.onAcceptGroupInvitation) {
+      return;
+    }
+    this.setState({
+      invitationBusy: true,
+      invitationError: null
+    });
+    this.props.onAcceptGroupInvitation(invitationId).then(result => {
+      this.setState({
+        invitationBusy: false,
+        invitationResult: result && result.status || 'joined'
+      });
+    }).catch(err => {
+      this.setState({
+        invitationBusy: false,
+        invitationError: err && err.message || '操作失败，请重试'
+      });
+    });
+  }
+  renderGroupInvitationCard(text, action) {
+    const {
+      invitationBusy,
+      invitationResult,
+      invitationError
+    } = this.state;
+    return (0,react_jsx_dev_runtime__WEBPACK_IMPORTED_MODULE_10__.jsxDEV)("div", {
+      className: "message-group-invitation",
+      children: [(0,react_jsx_dev_runtime__WEBPACK_IMPORTED_MODULE_10__.jsxDEV)("div", {
+        children: text
+      }, void 0, false), invitationResult == 'joined' ? (0,react_jsx_dev_runtime__WEBPACK_IMPORTED_MODULE_10__.jsxDEV)("em", {
+        children: "已加入群聊"
+      }, void 0, false) : invitationResult == 'pending_approval' ? (0,react_jsx_dev_runtime__WEBPACK_IMPORTED_MODULE_10__.jsxDEV)("em", {
+        children: "已提交申请，等待管理员通过"
+      }, void 0, false) : invitationResult ? (0,react_jsx_dev_runtime__WEBPACK_IMPORTED_MODULE_10__.jsxDEV)("em", {
+        children: invitationResult
+      }, void 0, false) : (0,react_jsx_dev_runtime__WEBPACK_IMPORTED_MODULE_10__.jsxDEV)("button", {
+        type: "button",
+        disabled: invitationBusy,
+        onClick: () => this.handleAcceptGroupInvitation(action.target_id),
+        children: invitationBusy ? '处理中…' : action.label || '立即加入'
+      }, void 0, false), invitationError ? (0,react_jsx_dev_runtime__WEBPACK_IMPORTED_MODULE_10__.jsxDEV)("small", {
+        className: "message-group-invitation-error",
+        children: invitationError
+      }, void 0, false) : null]
+    }, void 0, true);
+  }
   renderFailReason() {
     if (this.props.response || this.props.received != tinode_sdk__WEBPACK_IMPORTED_MODULE_2__.Tinode.MESSAGE_STATUS_FAILED && this.props.received != tinode_sdk__WEBPACK_IMPORTED_MODULE_2__.Tinode.MESSAGE_STATUS_FATAL) {
       return null;
@@ -2804,7 +2872,12 @@ 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' || this.props.head['x-im-type'] === 'system_action') && content && typeof content == 'object' && typeof content.text == 'string') {
+    const systemActions = content && typeof content == 'object' && Array.isArray(content.actions) ? content.actions : null;
+    const inviteAction = this.props.head && this.props.head['x-im-type'] === 'system_action' && systemActions && systemActions.find(a => a && a.type === 'group_invitation_accept');
+    let invitationCard = null;
+    if (inviteAction && typeof content.text == 'string') {
+      invitationCard = this.renderGroupInvitationCard(content.text, inviteAction);
+    } else 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;
@@ -2880,7 +2953,7 @@ class BaseChatMessage extends (react__WEBPACK_IMPORTED_MODULE_0___default().Pure
             className: "content-meta",
             children: [(0,react_jsx_dev_runtime__WEBPACK_IMPORTED_MODULE_10__.jsxDEV)("div", {
               className: textSizeClass,
-              children: [bundleCard || content, attachments]
+              children: [invitationCard || bundleCard || content, attachments]
             }, void 0, true), this.props.timestamp ? (0,react_jsx_dev_runtime__WEBPACK_IMPORTED_MODULE_10__.jsxDEV)(_received_marker_jsx__WEBPACK_IMPORTED_MODULE_6__["default"], {
               edited: this.props.edited,
               timestamp: this.props.timestamp,