```

feat(DeviceLoan): 添加设备搜索功能并优化借用流程

- 新增设备关键词搜索状态和输入框，支持按设备编码/名称搜索
- 优化借用设备选项过滤逻辑，排除已报废和借用中的设备
- 在打开借用弹窗时清空设备搜索关键词
- 更新借用设备选择下拉框提示文案

feat(DeviceManagement): 添加借用中设备状态

- 在设备状态列表中添加"借用中"状态选项
- 为"借用中"状态配置蓝色标签样式

feat(Messages): 实现群组邀请成员功能

- 添加邀请成员弹窗组件和相关状态管理
- 实现群主邀请成员加入群聊的功能接口调用
- 过滤可邀请用户列表，排除已在群内的成员
- 添加邀请成员按钮，仅群主可见
```

client/src/pages/Messages.jsx

@@ -1,6 +1,6 @@
 import React, { useState, useEffect, useRef } from 'react'
 import { Card, Button, Input, List, Badge, Modal, Form, Select, Tabs, Avatar, Empty, message, Popconfirm, Space, Tag, Tooltip, Popover, Image } from 'antd'
-import { PlusOutlined, SendOutlined, TeamOutlined, UserOutlined, ArrowLeftOutlined, DeleteOutlined, SettingOutlined, UserDeleteOutlined, CheckCircleFilled, ClockCircleOutlined, SmileOutlined, PictureOutlined, VideoCameraOutlined, PaperClipOutlined, FileOutlined, DownloadOutlined } from '@ant-design/icons'
+import { PlusOutlined, SendOutlined, TeamOutlined, UserOutlined, ArrowLeftOutlined, DeleteOutlined, SettingOutlined, UserDeleteOutlined, UserAddOutlined, CheckCircleFilled, ClockCircleOutlined, SmileOutlined, PictureOutlined, VideoCameraOutlined, PaperClipOutlined, FileOutlined, DownloadOutlined } from '@ant-design/icons'
 import axios from 'axios'
 
 const { TextArea } = Input
@@ -45,6 +45,8 @@ function Messages({ user }) {
   const [sending, setSending] = useState(false)
   const [createVisible, setCreateVisible] = useState(false)
   const [membersVisible, setMembersVisible] = useState(false)
+  const [inviteVisible, setInviteVisible] = useState(false)
+  const [inviteIds, setInviteIds] = useState([])
   const [createForm] = Form.useForm()
   const [creating, setCreating] = useState(false)
   const [uploading, setUploading] = useState(false)
@@ -242,6 +244,38 @@ function Messages({ user }) {
     }
   }
 
+  // 群主邀请成员加入群聊（拉人）
+  const handleInviteMembers = async () => {
+    if (!inviteIds.length) {
+      message.warning('请选择要邀请的成员')
+      return
+    }
+    try {
+      const res = await axios.post(`/api/chat/conversations/${activeConv.id}/members`, { user_ids: inviteIds })
+      if (res.data.success) {
+        message.success(res.data.message)
+        setInviteVisible(false)
+        setInviteIds([])
+        const list = await axios.get('/api/chat/conversations')
+        if (list.data.success) {
+          setConversations(list.data.data)
+          const conv = list.data.data.find(c => c.id === activeConv.id)
+          if (conv) {
+            setActiveConv(conv)
+            activeConvRef.current = conv
+          }
+        }
+      }
+    } catch (err) {
+      message.error(err.response?.data?.message || '邀请失败')
+    }
+  }
+
+  // 可邀请的用户（尚未在群内）
+  const inviteOptions = allUsers
+    .filter(u => !(activeConv?.members || []).some(m => m.id === u.id))
+    .map(u => ({ value: u.id, label: `${u.display_name || u.username}${u.role === 'admin' ? '（管理员）' : ''}` }))
+
   const otherOptions = allUsers.filter(u => u.id !== user?.id).map(u => ({
     value: u.id,
     label: (
@@ -507,6 +541,17 @@ function Messages({ user }) {
       footer={null}
       width={420}
     >
+      {activeConv?.creator_id === user?.id && (
+        <Button
+          type="primary"
+          icon={<UserAddOutlined />}
+          block
+          style={{ marginBottom: 12 }}
+          onClick={() => { setInviteIds([]); setInviteVisible(true) }}
+        >
+          邀请成员（拉人入群）
+        </Button>
+      )}
       <List
         dataSource={activeConv?.members || []}
         renderItem={(m) => (
@@ -543,6 +588,31 @@ function Messages({ user }) {
     </Modal>
   )
 
+  // ============ 邀请成员弹窗（仅群主，拉人） ============
+  const inviteModal = (
+    <Modal
+      title="邀请成员加入群聊"
+      open={inviteVisible}
+      onCancel={() => setInviteVisible(false)}
+      onOk={handleInviteMembers}
+      okText="邀请"
+      cancelText="取消"
+      width={420}
+    >
+      <Select
+        mode="multiple"
+        placeholder="选择要拉入群聊的成员"
+        value={inviteIds}
+        onChange={setInviteIds}
+        options={inviteOptions}
+        showSearch
+        optionFilterProp="label"
+        style={{ width: '100%' }}
+      />
+      <p style={{ color: '#999', fontSize: 12, marginTop: 8 }}>被邀请成员将收到系统通知，并立即加入群聊。</p>
+    </Modal>
+  )
+
   // ============ 布局 ============
   if (isMobile) {
     return (
@@ -553,6 +623,7 @@ function Messages({ user }) {
 
         {createModal}
         {membersModal}
+        {inviteModal}
       </div>
     )
   }
@@ -568,6 +639,7 @@ function Messages({ user }) {
 
       {createModal}
       {membersModal}
+      {inviteModal}
     </div>
   )
 }