feat: model undergraduate schools terms and exam queries

mobile/lib/features/school/school_selection_page.dart

@@ -1,14 +1,8 @@
 import 'package:flutter/material.dart';
 
 import '../../app/app_theme.dart';
-
-/// Only list schools whose login and import workflow is available.
-enum SupportedSchool {
-  uestcGraduate('电子科技大学（研究生）', '研究生课表与考试安排');
-
-  const SupportedSchool(this.label, this.description);
-  final String label, description;
-}
+import '../../domain/school_identity.dart';
+export '../../domain/school_identity.dart';
 
 class SchoolSelectionPage extends StatelessWidget {
   const SchoolSelectionPage({super.key, this.selected});