feat: extend optional HTML feedback to graduate imports in 0.7.8

mobile/lib/features/school/school_session.dart

@@ -7,6 +7,7 @@ import '../../data/json_schedule_import.dart';
 import '../../domain/exam_schedule.dart';
 import '../../domain/school_term.dart';
 import '../../services/diagnostic_log.dart';
+import '../../services/school_page_diagnostic.dart';
 import 'school_navigation_policy.dart';
 import 'school_page_adapter.dart';
 import 'school_exam_adapter.dart';
@@ -257,6 +258,7 @@ class SchoolSession extends ChangeNotifier {
     final closing = _logoutFuture;
     if (closing != null) await closing;
     if (serial != _openSerial) return;
+    SchoolPageDiagnostic.instance.clear();
     _timeout?.cancel();
     _poll?.cancel();
     _manualRead = false;
@@ -303,6 +305,7 @@ class SchoolSession extends ChangeNotifier {
       return;
     }
     final serial = ++_openSerial;
+    SchoolPageDiagnostic.instance.clear();
     _poll?.cancel();
     _timeout?.cancel();
     _pageGeneration++;
@@ -460,9 +463,8 @@ class SchoolSession extends ChangeNotifier {
           'term': selectedTerm?.id,
         },
       );
-      if (!hasOpened ||
-          generation != _pageGeneration ||
-          await web.currentUrl() != url) {
+      final liveUrl = await web.currentUrl();
+      if (!hasOpened || generation != _pageGeneration || liveUrl != url) {
         return;
       }
       if (evidence.terms.isNotEmpty) _liveTerms = evidence.terms;
@@ -480,6 +482,7 @@ class SchoolSession extends ChangeNotifier {
       }
       for (final page in evidence.pages) {
         if (page.kind != (requestingExams ? 'exams' : 'timetable')) continue;
+        SchoolPageDiagnostic.instance.remember(page.html, page.url);
         try {
           if (requestingExams) {
             final draft = SchoolExamAdapter.extract(page.html);
@@ -586,17 +589,23 @@ class SchoolSession extends ChangeNotifier {
       throw UnsupportedSchoolLayout();
     }
     final evidence = await _evidence(uri);
-    if (generation != _pageGeneration ||
-        await web.currentUrl() != uri.toString()) {
+    final liveUrl = await web.currentUrl();
+    if (!hasOpened ||
+        generation != _pageGeneration ||
+        liveUrl != uri.toString()) {
       throw UnsupportedSchoolLayout();
     }
     for (final page in evidence.pages) {
       if (page.kind != 'timetable') continue;
+      SchoolPageDiagnostic.instance.remember(page.html, page.url);
       try {
         final draft = await _reader.read(
           selectedTerm!.timetableUri,
           () async => page.html,
         );
+        if (!hasOpened || generation != _pageGeneration) {
+          throw UnsupportedSchoolLayout();
+        }
         if (draft.schoolTerm != selectedTerm) continue;
         return draft;
       } on UnsupportedSchoolLayout {
@@ -648,6 +657,7 @@ class SchoolSession extends ChangeNotifier {
   }
 
   void invalidateAuthentication() {
+    SchoolPageDiagnostic.instance.clear();
     _openSerial++;
     _pageGeneration++;
     _reader.invalidate();
@@ -667,6 +677,7 @@ class SchoolSession extends ChangeNotifier {
   }
 
   Future<void> _performLogout() async {
+    SchoolPageDiagnostic.instance.clear();
     _openSerial++;
     _pageGeneration++;
     _reader.invalidate();
@@ -697,6 +708,7 @@ class SchoolSession extends ChangeNotifier {
 
   @override
   void dispose() {
+    SchoolPageDiagnostic.instance.clear();
     hasOpened = false;
     _pageGeneration++;
     _reader.invalidate();