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/TeacherAttendanceView.vue

@@ -19,6 +19,7 @@ import { GridComponent, LegendComponent, TooltipComponent } from 'echarts/compon
 import { CanvasRenderer } from 'echarts/renderers'
 import http, { apiErrorMessage } from '../api/http'
 import { downloadApiFile, importExcel } from '../api/excel'
+import { academicTermLabel, academicTermOptionClass, defaultAcademicTermId } from '../utils/academicTerms'
 
 echarts.use([
   LineChart,
@@ -592,7 +593,7 @@ onMounted(async () => {
   window.addEventListener('resize', resizeCharts)
   clockTimer = window.setInterval(() => { now.value = Date.now() }, 1000)
   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 loadTasks()
 })
 
@@ -616,7 +617,7 @@ onUnmounted(() => {
 
     <section class="attendance-toolbar">
       <el-select v-model="termId" clearable placeholder="全部学期" @change="loadTasks">
-        <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 {{ tasks.length }} 个教学班</span>
       <el-radio-group v-model="activeMode" class="mode-switch" size="small">