学年学期页面新增“设为当前”“归档”“撤销归档”，当前学期不能归档、删除或直接取消；已归档学期需先撤销才能重新设为当前。[BaseDataController.cs (line 286)](/E:/jiaowu/src/Jiaowu.Api/Controllers/BaseDataController.cs:286)

切换后，其他学期自动变为历史态；已归档学期进一步弱化。所有主要学期选择器统一默认当前，并显示“当前 / 历史 / 已归档”。[academicTerms.ts (line 1)](/E:/jiaowu/web/src/utils/academicTerms.ts:1)
桌面使用分层表格，390px 手机端改为独立学期卡片，操作不会再挤压表格。[BaseDataView.vue (line 211)](/E:/jiaowu/web/src/views/BaseDataView.vue:211)
归档定义为“历史显示状态”，不是成绩冻结：补考成绩仍可录入并回写，已发布成绩仍可走成绩更正审批。
已加入 SQLite 开发迁移、MySQL 正式迁移和切换/归档/撤销测试。[20260726143000_AcademicTermArchiving.cs (line 1)](/E:/jiaowu/src/Jiaowu.Api/Infrastructure/Persistence/Migrations/MySql/20260726143000_AcademicTermArchiving.cs:1)

web/src/views/TeacherRosterView.vue

@@ -3,6 +3,7 @@ import { onMounted, ref } from 'vue'
 import { Download, Refresh } from '@element-plus/icons-vue'
 import http, { apiErrorMessage } from '../api/http'
 import { downloadApiFile } from '../api/excel'
+import { academicTermLabel, academicTermOptionClass, defaultAcademicTermId } from '../utils/academicTerms'
 
 const loading = ref(false)
 const detailLoading = ref(false)
@@ -59,7 +60,7 @@ async function exportRoster() {
 
 onMounted(async () => {
   terms.value = (await http.get('/base-data/terms')).data
-  termId.value = terms.value.find((item: any) => item.isCurrent)?.id
+  termId.value = defaultAcademicTermId(terms.value)
   await loadOfferings()
 })
 </script>
@@ -77,7 +78,7 @@ onMounted(async () => {
 
     <section class="roster-toolbar">
       <el-select v-model="termId" clearable placeholder="全部学期" @change="loadOfferings">
-        <el-option v-for="term in terms" :key="term.id" :label="term.name" :value="term.id" />
+        <el-option v-for="term in terms" :key="term.id" :label="academicTermLabel(term)" :value="term.id" :class="academicTermOptionClass(term)" />
       </el-select>
       <span>共 {{ offerings.length }} 个教学班</span>
     </section>