feat: deliver Riverside Schedule seven-day grid and school HTML import

mobile/lib/features/school/school_session.dart

@@ -35,6 +35,9 @@ class SchoolSession extends ChangeNotifier {
             return NavigationDecision.navigate;
           },
           onPageStarted: (_) {
+            _pageGeneration++;
+            _reader.invalidate();
+            pendingDraft = null;
             if (!hasOpened) {
               return;
             }
@@ -72,6 +75,7 @@ class SchoolSession extends ChangeNotifier {
       hasOpened = false,
       formReady = false;
   bool get busy => _loading || _submitting || _reader.busy;
+  int _pageGeneration = 0;
   ImportDraft? pendingDraft;
   String message = '请通过学校统一身份认证登录。';
   String get statusLabel => switch (connectionState) {
@@ -79,7 +83,7 @@ class SchoolSession extends ChangeNotifier {
     SchoolConnectionState.authenticating => '请在学校页面完成认证',
     SchoolConnectionState.connected => '学校认证已确认',
     SchoolConnectionState.expired => '学校登录已过期',
-    SchoolConnectionState.unknown => '学校页面已打开 · 课表识别待联调',
+    SchoolConnectionState.unknown => '学校页面已打开 · 等待完整课表',
   };
   static final authUrl = Uri.parse(
     'https://idas.uestc.edu.cn/authserver/login',
@@ -134,26 +138,33 @@ class SchoolSession extends ChangeNotifier {
       return;
     }
     _loading = false;
+    final generation = _pageGeneration;
     final uri = Uri.tryParse(url);
     if (uri != null && SchoolNavigationPolicy.canInjectCredentials(uri)) {
       connectionState = connectionState == SchoolConnectionState.connected
           ? SchoolConnectionState.expired
           : SchoolConnectionState.authenticating;
       try {
-        formReady = _truth(
+        final ready = _truth(
           await web.runJavaScriptReturningResult(_readyScript),
         );
+        if (!hasOpened || generation != _pageGeneration) return;
+        formReady = ready;
       } catch (_) {
+        if (!hasOpened || generation != _pageGeneration) return;
         formReady = false;
       }
-      message = formReady ? '可以使用河畔界面登录；验证码会在学校页面完成。' : '请使用学校原页面完成认证。';
+      message = formReady ? '可以使用应用界面登录；验证码会在学校页面完成。' : '请使用学校原页面完成认证。';
     } else if (uri != null && SchoolNavigationPolicy.isTimetable(uri)) {
       connectionState = SchoolConnectionState.unknown;
       message = '已打开课表页面，正在核对课程结构。';
       try {
-        pendingDraft = await readTimetable();
+        final draft = await readTimetable();
+        if (!hasOpened || generation != _pageGeneration) return;
+        pendingDraft = draft;
         connectionState = SchoolConnectionState.connected;
       } catch (error) {
+        if (!hasOpened || generation != _pageGeneration) return;
         message = error is UnsupportedSchoolLayout
             ? error.toString()
             : '课表读取未完成，已有课表保持不变。';
@@ -238,6 +249,8 @@ class SchoolSession extends ChangeNotifier {
   }
 
   Future<void> logout() async {
+    _pageGeneration++;
+    _reader.invalidate();
     hasOpened = false;
     await WebViewCookieManager().clearCookies();
     await web.clearCache();