fix: import unpublished exam rooms and add opt-in school HTML feedback

mobile/test/widgets/undergraduate_auth_test.dart

@@ -9,6 +9,7 @@ import 'package:hepan_everyday/features/school/undergraduate/page_probe.dart';
 import 'package:hepan_everyday/app/app_controller.dart';
 import 'package:hepan_everyday/domain/app_snapshot.dart';
 import 'package:hepan_everyday/domain/school_term.dart';
+import 'package:hepan_everyday/services/school_page_diagnostic.dart';
 
 import '../support/fake_school_web.dart';
 import '../support/fakes.dart';
@@ -82,6 +83,7 @@ void main() {
     await tester.pumpAndSettle();
     expect(controller.snapshot.courses, hasLength(18));
     expect(find.text('打开'), findsOneWidget);
+    SchoolPageDiagnostic.instance.clear();
   });
   testWidgets('cross school replacement can be cancelled without saving', (
     tester,
@@ -100,6 +102,7 @@ void main() {
     await tester.pumpAndSettle();
     expect(controller.snapshot.toJson(), previous);
     expect(find.text('导入当前课表'), findsOneWidget);
+    SchoolPageDiagnostic.instance.clear();
   });
   testWidgets('failed saving stays on the browser and can be retried', (
     tester,
@@ -114,6 +117,7 @@ void main() {
     await tester.tap(find.text('重试保存'));
     await tester.pumpAndSettle();
     expect(controller.snapshot.courses, hasLength(18));
+    SchoolPageDiagnostic.instance.clear();
   });
   testWidgets('an obsolete deferred save does not strand a newer import', (
     tester,
@@ -125,5 +129,6 @@ void main() {
     platform.delegate.finished(platform.web.url!);
     await tester.pumpAndSettle();
     expect(controller.snapshot.courses, hasLength(18));
+    SchoolPageDiagnostic.instance.clear();
   });
 }