fix: import unpublished exam rooms and add opt-in school HTML feedback

mobile/lib/features/feedback/feedback_page.dart

@@ -3,6 +3,7 @@ import 'package:flutter/material.dart';
 
 import '../../app/app_theme.dart';
 import '../../services/diagnostic_log.dart';
+import '../../services/school_page_diagnostic.dart';
 import 'feedback_submission.dart';
 
 typedef FeedbackAttachmentPicker = Future<FeedbackAttachment?> Function();
@@ -34,6 +35,7 @@ class _FeedbackPageState extends State<FeedbackPage> {
   var _success = false;
   var _uncertain = false;
   var _includeLogs = false;
+  var _includeHtml = false;
   String? _error;
   FeedbackSubmission? _pendingSubmission;
 
@@ -107,6 +109,20 @@ class _FeedbackPageState extends State<FeedbackPage> {
     FocusScope.of(context).unfocus();
     setState(() => _submitting = true);
     try {
+      final html =
+          _pendingSubmission == null &&
+              _kind == FeedbackKind.problem &&
+              _includeHtml
+          ? SchoolPageDiagnostic.instance.export()
+          : null;
+      if (_pendingSubmission == null &&
+          _kind == FeedbackKind.problem &&
+          _includeHtml &&
+          html == null) {
+        throw const FeedbackException(
+          '最近10分钟没有可用的本科导入页面。请返回学校页面再尝试导入，然后提交反馈；也可以取消附带HTML。',
+        );
+      }
       _pendingSubmission ??= _kind == FeedbackKind.problem
           ? FeedbackSubmission.problem(
               id: FeedbackSubmission.newId(),
@@ -117,6 +133,7 @@ class _FeedbackPageState extends State<FeedbackPage> {
               diagnosticLog: _includeLogs
                   ? await DiagnosticLog.instance.export()
                   : null,
+              diagnosticHtml: html,
             )
           : FeedbackSubmission.development(
               id: FeedbackSubmission.newId(),
@@ -128,6 +145,9 @@ class _FeedbackPageState extends State<FeedbackPage> {
         _error = null;
       });
       await widget.sender.send(_pendingSubmission!);
+      if (_pendingSubmission?.diagnosticHtml != null) {
+        SchoolPageDiagnostic.instance.clear();
+      }
       if (mounted) setState(() => _success = true);
     } on FeedbackDeliveryUncertain catch (error) {
       if (mounted) {
@@ -275,6 +295,58 @@ class _FeedbackPageState extends State<FeedbackPage> {
                                 : (value) {
                                     setState(() {
                                       _includeLogs = value ?? false;
+                                      if (!_includeLogs) _includeHtml = false;
+                                      _pendingSubmission = null;
+                                      _error = null;
+                                    });
+                                  },
+                          ),
+                          CheckboxListTile(
+                            key: const Key('feedback-html'),
+                            contentPadding: EdgeInsets.zero,
+                            title: const Text('附带最近一次本科导入页面HTML'),
+                            subtitle: const Text(
+                              '需先勾选日志。网页可能含姓名、学号、课程、教师和考场信息，仅保留最近10分钟，单独作为邮件附件发送。',
+                            ),
+                            value: _includeHtml,
+                            onChanged: _submitting || !_includeLogs
+                                ? null
+                                : (value) async {
+                                    var accepted = value ?? false;
+                                    if (accepted) {
+                                      accepted =
+                                          await showDialog<bool>(
+                                            context: context,
+                                            builder: (context) => AlertDialog(
+                                              title: const Text('附带网页排查资料？'),
+                                              content: const Text(
+                                                '附件可能包含你的姓名、学号、课程及考试信息，将发送给开发者用于排查导入问题。密码、验证码、Cookie和认证参数不会包含在附件中。',
+                                              ),
+                                              actions: [
+                                                TextButton(
+                                                  onPressed: () =>
+                                                      Navigator.pop(
+                                                        context,
+                                                        false,
+                                                      ),
+                                                  child: const Text('取消'),
+                                                ),
+                                                FilledButton(
+                                                  onPressed: () =>
+                                                      Navigator.pop(
+                                                        context,
+                                                        true,
+                                                      ),
+                                                  child: const Text('同意附带'),
+                                                ),
+                                              ],
+                                            ),
+                                          ) ??
+                                          false;
+                                    }
+                                    if (!mounted) return;
+                                    setState(() {
+                                      _includeHtml = accepted;
                                       _pendingSubmission = null;
                                       _error = null;
                                     });