fix(config): 默认头像改用 ImageUpload 图片上传控件

server/MiAssessment/src/MiAssessment.Admin/admin-web/src/views/system/config/user.vue

@@ -56,32 +56,12 @@
 
         <el-form-item label="默认头像">
           <div class="avatar-config">
-            <div class="avatar-preview">
-              <el-image
-                v-if="state.formData.default_avatar"
-                :src="state.formData.default_avatar"
-                fit="cover"
-                class="avatar-img"
-              >
-                <template #error>
-                  <div class="avatar-placeholder">
-                    <el-icon :size="24"><Picture /></el-icon>
-                  </div>
-                </template>
-              </el-image>
-              <div v-else class="avatar-placeholder">
-                <el-icon :size="24"><User /></el-icon>
-                <span class="placeholder-text">系统生成</span>
-              </div>
-            </div>
-            <div class="avatar-input">
-              <el-input
-                v-model="state.formData.default_avatar"
-                placeholder="请输入默认头像URL，留空则使用系统自动生成"
-                clearable
-              />
-              <div class="form-item-tip">填写图片URL作为所有新用户的默认头像，留空则系统自动生成唯一头像</div>
-            </div>
+            <ImageUpload
+              v-model="state.formData.default_avatar"
+              placeholder="点击上传默认头像"
+              :show-url-input="false"
+              tip="上传图片作为所有新用户的默认头像，不上传则系统自动生成唯一头像"
+            />
           </div>
         </el-form-item>
       </el-form>
@@ -102,7 +82,7 @@
  */
 import { reactive, computed, onMounted } from 'vue'
 import { ElMessage } from 'element-plus'
-import { Picture, User } from '@element-plus/icons-vue'
+import ImageUpload from '@/components/ImageUpload/index.vue'
 import {
   getUserConfig,
   updateUserConfig,
@@ -223,41 +203,6 @@ onMounted(() => {
 .avatar-config {
   display: flex;
   align-items: flex-start;
-  gap: 16px;
-}
-
-.avatar-preview {
-  flex-shrink: 0;
-  width: 80px;
-  height: 80px;
-  border-radius: 8px;
-  overflow: hidden;
-  border: 1px solid #ebeef5;
-}
-
-.avatar-img {
-  width: 80px;
-  height: 80px;
-}
-
-.avatar-placeholder {
-  width: 100%;
-  height: 100%;
-  display: flex;
-  flex-direction: column;
-  align-items: center;
-  justify-content: center;
-  background: #f5f7fa;
-  color: #909399;
-}
-
-.placeholder-text {
-  font-size: 10px;
-  margin-top: 4px;
-}
-
-.avatar-input {
-  flex: 1;
 }
 
 .form-actions {