style(teacher/taskHomePage): 调整学生列表项的样式和默认名称显示

优化学生列表项的编号和姓名样式，增加可读性和美观性
为没有名字的学生设置默认显示'未命名'

 <!--
  * @Date: 2025-11-19 21:00:00
  * @LastEditors: hookehuyr hookehuyr@gmail.com
- * @LastEditTime: 2025-12-02 18:48:32
+ * @LastEditTime: 2025-12-02 21:30:35
  * @FilePath: /mlaj/src/views/teacher/taskHomePage.vue
  * @Description: 教师端作业主页（头部介绍、统计、日历与学生完成情况；数据Mock）
 -->
@@ -94,8 +94,8 @@
                     class="studentItem relative rounded-md h-16 flex flex-col items-center justify-center text-center border overflow-hidden"
                     :class="stu.completed ? 'bg-white border-green-500 text-green-600' : 'bg-gray-100 border-gray-300 text-gray-500'"
                     @click="go_student_record(stu)">
-                    <div class="text-sm font-semibold">{{ idx + 1 }}</div>
-                    <div class="text-sm mt-1">{{ stu.name }}</div>
+                    <div class="text-[10px] font-bold opacity-60 mb-0.5">{{ idx + 1 }}</div>
+                    <div class="text-xs font-medium leading-tight break-words line-clamp-2 px-1">{{ stu.name }}</div>
                     <img v-if="stu.completed" :src="checkCorner" alt="checked" class="cornerIcon" />
                 </div>
             </div>
@@ -314,7 +314,7 @@ function on_date_select(val) {
 const students_status = computed(() => {
     return user_list.value.map(stu => ({
         id: stu.id,
-        name: stu.name,
+        name: stu.name || '未命名',
         completed: !!stu.is_commit,
         avatar: stu.avatar // 保留头像字段以便将来使用
     }))