fix: harden school imports and add optional feedback diagnostics

mobile/test/school/school_session_flow_test.dart

@@ -1,4 +1,7 @@
 import 'dart:async';
+import 'dart:convert';
+
+import 'package:hepan_everyday/services/diagnostic_log.dart';
 
 import 'package:flutter_test/flutter_test.dart';
 import 'package:webview_flutter_platform_interface/webview_flutter_platform_interface.dart';
@@ -26,6 +29,30 @@ void main() {
     platform.delegate.finished(url);
   }
 
+  test('login diagnostic breadcrumbs distinguish probe and network failures without raw details', () async {
+    await session.openTimetable(term: SchoolTerm(73));
+    session.setReadingActive(true);
+    platform.web.javascript = (_) async => throw StateError('PRIVATE_TICKET');
+    navigate('https://yjsjy.uestc.edu.cn/pyxx/home/index');
+    await flushSchoolEvents();
+    var log = utf8.decode(await DiagnosticLog.instance.export());
+    expect(log, contains('school_probe_failed'));
+    expect(log, isNot(contains('PRIVATE_TICKET')));
+    platform.delegate.resourceError(
+      WebResourceError(
+        errorCode: -2,
+        description: 'PRIVATE_NETWORK_DETAIL',
+        isForMainFrame: true,
+        url: platform.web.url,
+      ),
+    );
+    await flushSchoolEvents();
+    log = utf8.decode(await DiagnosticLog.instance.export());
+    expect(log, contains('web_resource_error'));
+    expect(log, contains('"status":-2'));
+    expect(log, isNot(contains('PRIVATE_NETWORK_DETAIL')));
+  });
+
   test('graduate logout function automatically opens timetable without an exit anchor', () async {
     await session.openTimetable(term: SchoolTerm(73));
     platform.web.javascript = (script) async =>

mobile/test/school/undergraduate_exam_batch_test.dart

@@ -82,6 +82,10 @@ void main() {
       await finish();
       expect(session.pendingExams!.records, hasLength(12));
       expect(session.pendingExams!.requestedExamTypes, {1, 2, 3});
+      final completedGeneration = session.pageGeneration;
+      platform.delegate.started('https://eams.uestc.edu.cn/eams/');
+      expect(session.pendingExams, isNull);
+      expect(session.pageGeneration, greaterThan(completedGeneration));
     },
   );
   test('last type failure never publishes partial results', () async {

mobile/test/school/undergraduate_timetable_adapter_test.dart

@@ -9,6 +9,21 @@ import 'package:hepan_everyday/data/schedule_file_import.dart';
 import 'package:hepan_everyday/domain/school_identity.dart';
 
 void main() {
+  test('unrecognized activity writes and incomplete declarations reject the entire timetable', () {
+    const valid =
+        'activity = new TaskActivity("T", "教师", "C", "课程(C.01)", "R", "教室", "010"); '
+        'index = 0*unitCount+0; table0.activities[index][table0.activities[index].length]=activity;';
+    for (final extra in [
+      'table0.activities[11][table0.activities[11].length]=activity;',
+      'activity = new TaskActivity("T", "教师", "C", "另一课程(C.02)", "R", "教室", "010")\n'
+          'index = 0*unitCount+1; table0.activities[index][table0.activities[index].length]=activity;',
+    ]) {
+      expect(
+        () => parseActivityData('$valid $extra', unitCount: 12),
+        throwsFormatException,
+      );
+    }
+  });
   final uri = Uri.parse(
     'https://eams.uestc.edu.cn/eams/courseTableForStd.action',
   );