style: 学生弹窗归属用户改为只读红色标签

- 归属用户字段改为只读展示
- 展示格式：会员昵称(手机号)
- 红色字体显示
- 移除选择/清除按钮

frontend/ruoyi-ui/src/views/business/student/components/StudentDialog.vue

@@ -53,26 +53,14 @@
           @change="handleSchoolChange"
         />
       </el-form-item>
-      <el-form-item label="归属用户" prop="memberId">
-        <div style="display: flex; gap: 8px; width: 100%">
-          <el-input 
-            v-model="form.memberDisplay" 
-            placeholder="点击选择归属用户" 
-            readonly 
-            style="flex: 1"
-          />
-          <el-button @click="handleSelectMember">选择</el-button>
-          <el-button v-if="form.memberId" @click="handleClearMember">清除</el-button>
-        </div>
+      <el-form-item label="归属用户">
+        <span style="color: #F56C6C;">{{ form.memberDisplay || '暂无归属用户' }}</span>
       </el-form-item>
     </el-form>
     <template #footer>
       <el-button @click="visible = false">取消</el-button>
       <el-button type="primary" @click="handleSubmit" :loading="submitLoading">确定</el-button>
     </template>
-
-    <!-- 会员选择弹窗 -->
-    <MemberSelectDialog ref="memberSelectRef" @select="handleMemberSelected" />
   </el-dialog>
 </template>
 
@@ -84,7 +72,6 @@
 import { ElMessage } from 'element-plus'
 import { reactive, ref } from 'vue'
 import request from '@/utils/request'
-import MemberSelectDialog from './MemberSelectDialog.vue'
 
 const emit = defineEmits(['success'])
 
@@ -93,7 +80,6 @@ const isEdit = ref(false)
 const formRef = ref(null)
 const formLoading = ref(false)
 const submitLoading = ref(false)
-const memberSelectRef = ref()
 
 // 学校树数据
 const schoolTreeData = ref([])
@@ -202,23 +188,6 @@ const open = async (row = null) => {
   formLoading.value = false
 }
 
-// 选择会员
-const handleSelectMember = () => {
-  memberSelectRef.value?.open()
-}
-
-// 会员选择回调
-const handleMemberSelected = (member) => {
-  form.memberId = member.memberId
-  form.memberDisplay = `${member.nickname || '未设置昵称'}（${member.phone}）`
-}
-
-// 清除会员
-const handleClearMember = () => {
-  form.memberId = null
-  form.memberDisplay = ''
-}
-
 // 提交
 const handleSubmit = async () => {
   try {