fixed guardian login edge cases and misleading placeholders on failed loads

CLAUDE.md

@@ -1,6 +1,6 @@
 # MarianumMobile Client
 
-Flutter-App für die Schul-Community: Webuntis-Stundenplan, Nextcloud Talk + Files, Custom MHSL-Backend (Breaker, Custom Events, Push).
+Flutter-App für die Schul-Community: Stundenplan, Ticker, Newsletter & Co. über das MarianumConnect-Backend, Nextcloud Talk + Files. Zwei Kontoarten: Schul-Konto (Schüler/Lehrer, Benutzername + Passwort) und Eltern-Konto (passwortlos per E-Mail-Code/App-Link, sieht die Stundenpläne der zugeordneten Kinder und erhält Elternbriefe, kein Talk/Files).
 
 ## Stack
 
@@ -16,7 +16,10 @@ Flutter-App für die Schul-Community: Webuntis-Stundenplan, Nextcloud Talk + Fil
 
 ```
 lib/
-├── api/                    HTTP-Layer pro Backend (mhsl/, marianumcloud/, webuntis/, holidays/)
+├── api/                    HTTP-Layer pro Backend (marianumconnect/, marianumcloud/, mhsl/ Legacy, demo/)
+├── session/                Session-Modell (CredentialSession / GuardianSession), SessionManager, SessionLifecycle
+├── access/                 UserRole, AccessRequirement (Gating von Modulen/Settings)
+├── auth_link/              Eltern-Login: App-Link-Listener, Link-Parser, Geräte-Bindung
 ├── state/app/modules/      BLoC pro Feature-Modul (timetable, chat, chat_list, files, ...)
 ├── state/app/infrastructure LoadableState<T>, DataLoader, geteilte BLoC-Bausteine
 ├── view/                   Screens
@@ -51,6 +54,14 @@ lib/
 
 **Settings:** Pro Feature ein Freezed-Modell unter `lib/storage/`, persistiert via HydratedBloc.
 
+**Session:** Die aktive Sitzung liegt in `SessionManager().current` (`lib/session/`). Nextcloud-Zugriffe nur über `SessionManager().requireNextcloud()` – Eltern-Sessions haben keine Nextcloud-Identität. Abmelden ausschließlich über `SessionLifecycle.signOut()`. Die Keychain-Keys in `SessionKeys` sind eingefroren (Bestandsinstallationen, iOS-NSE).
+
+**Rollen & Zuschnitt:** Views verzweigen nie auf Rollen. Module und Settings-Sections deklarieren `AccessRequirement`s (`nextcloud`, `guardian`; `AppModule.requirements`, `Settings._sections`); Views bekommen ein Subjekt + eine Policy, die an genau einer Stelle als pure Funktion aufgelöst wird (Vorbild: `TimetableSubject` + `TimetablePolicy.resolve`, `AbsenceFormPolicy`). `UserRole` nur für Anzeige/Policy-Ableitung.
+
+**Stundenplan:** Ein `TimetableBloc(subject: …)` für alle Fälle (eigener Plan, Fremdplan, Kind). Den globalen Bloc stellt `PrimaryTimetableScope` bereit und tauscht ihn beim Kindwechsel aus; page-scoped Fremdpläne nutzen `ScopedTimetableBloc`. Die Kinderauswahl (`ChildSelectionCubit`) ist modulübergreifend.
+
+**Elternbriefe:** Modul `parentLetters` (nur Eltern-Sessions, `AccessRequirement.guardian`): Lehrer-Mitteilungen aus MarianumConnect mit Gelesen-Status, Kenntnisnahme/Auswahl/Unterschrift pro Kind, Thread und Anhängen. Der Posteingang (`ParentLettersBloc`) ist global (Modul-Badge, Push-Refresh), ein Brief ist page-scoped (`ParentLetterBloc`). Ob und wie geantwortet werden darf, entscheidet der Server (`editable`); `ParentLetterFormPolicy.resolve` macht daraus das Formular. Push: Connect-Direct-Push `type: parent-letter`, Tap-Routing allein über `parentLetterId`. Alle Benachrichtigungs-Taps (lokal gerendert wie FCM) werden von `resolvePushTarget` (`lib/push/push_target.dart`) aufgelöst und in `NotificationTasks.openPushTarget` navigiert – neue Push-Ziele nur dort ergänzen.
+
 ## Build / Run
 
 ```bash
@@ -65,13 +76,12 @@ flutter test                                                 # Tests (siehe test
 
 | Backend                   | Pfad                  | Zweck                                  |
 |---------------------------|-----------------------|----------------------------------------|
-| Webuntis                  | `lib/api/webuntis/`   | Stundenplan, Klassen, Räume, Lehrer    |
+| MarianumConnect (Bearer)  | `lib/api/marianumconnect/` | Auth, Stundenplan (Webuntis-Proxy), Ticker, Newsletter, Ferien, Abwesenheit, Elternbriefe, Capabilities, Push |
 | Nextcloud (Talk + WebDAV) | `lib/api/marianumcloud/` | Chats, Datei-Verwaltung             |
-| Custom MHSL-Server        | `lib/api/mhsl/`       | Breaker, Custom Events, Notify, Noten  |
-| Holiday-Calendar          | `lib/api/holidays/`   | Ferien                                 |
+| MHSL (Legacy)             | `lib/api/mhsl/`       | nur noch Einmal-Migration der Custom Events |
 
 `nextcloud`-Paket ist auf einen Custom-Fork gepinnt (siehe `pubspec.yaml` `dependency_overrides`).
 
 ## Tests
 
-`test/` deckt aktuell nur Kern-Funktionen ab (DateTime-Extensions, AsyncActionController, LessonResolver). Beim Hinzufügen neuer pure-function-Helper bitte Test mit dazu.
+`test/` deckt vor allem pure Funktionen ab (DateTime-Extensions, Stundenplan-Logik, Session-Codec, Policies, Eltern-Login-Controller). Beim Hinzufügen neuer pure-function-Helper bitte Test mit dazu.

android/app/src/main/AndroidManifest.xml

@@ -41,6 +41,23 @@
                 <data android:mimeType="video/*" />
                 <data android:mimeType="application/*" />
             </intent-filter>
+            <!-- Guardian login mail link (App Link). Verified via
+                 /.well-known/assetlinks.json on both hosts. -->
+            <intent-filter android:autoVerify="true">
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+                <data android:scheme="https" />
+                <data android:host="connect.marianum-fulda.de" />
+                <data android:host="connect-beta.marianum-fulda.de" />
+                <data android:path="/app/guardian-login" />
+            </intent-filter>
+            <!-- The app routes links itself (GuardianLinkListener); Flutter's
+                 built-in handling would push the path as a named route onto a
+                 MaterialApp that only has `home`. -->
+            <meta-data
+                android:name="flutter_deeplinking_enabled"
+                android:value="false" />
         </activity>
         <!-- Don't delete the meta-data below.
              This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->

integration_test/screenshot_test.dart

@@ -106,12 +106,14 @@ void _log(String message) => debugPrint('SHOTS: $message');
 Future<void> _login(WidgetTester tester) async {
   final loginVisible = await _pumpUntil(
     tester,
-    find.byKey(const Key('login-username-field')),
+    find.byKey(const Key('login-audience-school')),
   );
   if (!loginVisible) {
     _log('kein Login-Screen sichtbar – bereits angemeldet, überspringe Login');
     return;
   }
+  await tester.tap(find.byKey(const Key('login-audience-school')));
+  await _pumpUntil(tester, find.byKey(const Key('login-username-field')));
   await tester.enterText(
     find.byKey(const Key('login-username-field')),
     'demo@screenshots',

ios/Runner/Info.plist

@@ -37,6 +37,8 @@
 		</array>
 		<key>CFBundleVersion</key>
 		<string>$(FLUTTER_BUILD_NUMBER)</string>
+		<key>FlutterDeepLinkingEnabled</key>
+		<false/>
 		<key>LSRequiresIPhoneOS</key>
 		<true/>
 		<key>NSCameraUsageDescription</key>

ios/Runner/Runner.entitlements

@@ -4,6 +4,11 @@
 <dict>
 	<key>aps-environment</key>
 	<string>development</string>
+	<key>com.apple.developer.associated-domains</key>
+	<array>
+		<string>applinks:connect.marianum-fulda.de</string>
+		<string>applinks:connect-beta.marianum-fulda.de</string>
+	</array>
 	<key>com.apple.security.application-groups</key>
 	<array>
 		<string>group.eu.mhsl.marianum.mobile.client.widget</string>

lib/access/access_requirement.dart

@@ -0,0 +1,17 @@
+import '../session/session.dart';
+
+/// Backend identity a feature needs. Modules and settings sections declare
+/// these; anything whose requirements the session does not meet is hidden.
+enum AccessRequirement {
+  nextcloud,
+  guardian;
+
+  bool isMetBy(Session? session) => switch (this) {
+    AccessRequirement.nextcloud => session?.nextcloud != null,
+    AccessRequirement.guardian => session is GuardianSession,
+  };
+}
+
+extension AccessRequirements on Set<AccessRequirement> {
+  bool areMetBy(Session? session) => every((r) => r.isMetBy(session));
+}

lib/access/user_role.dart

@@ -0,0 +1,20 @@
+/// Account role as reported by MarianumConnect. Only used for display and for
+/// deriving policies; features gate on capabilities and requirements instead
+/// of comparing roles.
+enum UserRole {
+  student,
+  teacher,
+  staff,
+  parent,
+  unknown;
+
+  /// Unknown or missing values map to [unknown] so a new server-side role
+  /// never breaks older app versions.
+  static UserRole parse(String? wire) => switch (wire) {
+    'STUDENT' => UserRole.student,
+    'TEACHER' => UserRole.teacher,
+    'STAFF' => UserRole.staff,
+    'PARENT' => UserRole.parent,
+    _ => UserRole.unknown,
+  };
+}

lib/api/demo/data/demo_capabilities.dart

@@ -1,5 +1,7 @@
 import '../../../state/app/modules/capabilities/bloc/capabilities_state.dart';
 import '../../../state/app/modules/nextcloud_capabilities/bloc/nextcloud_capabilities_state.dart';
+import '../../marianumconnect/queries/get_capabilities/guardian_child.dart';
+import '../demo_persona.dart';
 
 /// Demo fixtures for the mobile capability flags — everything granted so the
 /// demo persona sees every feature (incl. push) as available and the timetable
@@ -17,6 +19,27 @@ class DemoCapabilities {
     userType: 'STUDENT',
     loaded: true,
   );
+
+  /// Guardian persona with two children, so the child switcher is visible.
+  static CapabilitiesState guardianState() => const CapabilitiesState(
+    pushNotifications: true,
+    userType: 'PARENT',
+    children: [
+      GuardianChild(
+        id: 'demo-child-1',
+        firstName: DemoPersona.studentFirstName,
+        lastName: 'Hoffmann',
+        className: DemoPersona.className,
+      ),
+      GuardianChild(
+        id: 'demo-child-2',
+        firstName: 'Jonas',
+        lastName: 'Hoffmann',
+        className: '6a',
+      ),
+    ],
+    loaded: true,
+  );
 }
 
 /// Demo fixtures for the Nextcloud `files_sharing` capabilities — a permissive

lib/api/demo/data/demo_parent_letters.dart

@@ -0,0 +1,273 @@
+import '../../marianumconnect/queries/parent_letters/parent_letter_models.dart';
+import '../demo_persona.dart';
+
+/// Demo inbox of the guardian persona: one letter per variant (information,
+/// acknowledgement, choice, signature, answered, expired, thread, attachment).
+/// Child ids match [DemoCapabilities.guardianState].
+class DemoParentLetters {
+  const DemoParentLetters._();
+
+  static const _lena = 'demo-child-1';
+  static const _jonas = 'demo-child-2';
+
+  static final Set<String> _readInSession = {};
+
+  static void markRead(String letterId) => _readInSession.add(letterId);
+
+  static ParentLetterListResponse list() {
+    final items = [for (final letter in _letters()) letter.summary];
+    return ParentLetterListResponse(
+      items: items,
+      unreadCount: items.where((letter) => !letter.read).length,
+      openCount: items
+          .where((letter) => letter.status == ParentLetterStatus.open)
+          .length,
+    );
+  }
+
+  static ParentLetterDetail detail(String letterId) {
+    final letters = _letters();
+    return letters.firstWhere(
+      (letter) => letter.summary.id == letterId,
+      orElse: () => letters.first,
+    );
+  }
+
+  static ParentLetterPerson _teacher(int index) =>
+      ParentLetterPerson(displayName: DemoPersona.teachers[index].name);
+
+  static const _participation = ParentLetterField(
+    id: 'participation',
+    type: ParentLetterFieldType.singleChoice,
+    label: 'Nimmt Ihr Kind teil?',
+    isRequired: true,
+    options: [
+      ParentLetterOption(id: 'yes', label: 'Ja'),
+      ParentLetterOption(id: 'no', label: 'Nein'),
+    ],
+  );
+
+  static List<ParentLetterDetail> _letters() {
+    final now = DateTime.now();
+    ParentLetterDetail letter({
+      required String id,
+      required String subject,
+      required ParentLetterPerson sender,
+      required Duration age,
+      required String body,
+      required List<String> childIds,
+      bool read = true,
+      ParentLetterStatus status = ParentLetterStatus.info,
+      ParentLetterRequest? request,
+      List<ParentLetterChildState> children = const [],
+      List<ParentLetterAttachment> attachments = const [],
+      ParentLetterThread thread = const ParentLetterThread(enabled: true),
+    }) => ParentLetterDetail(
+      summary: ParentLetterSummary(
+        id: id,
+        subject: subject,
+        preview: body.replaceAll('\n', ' ').trim(),
+        sender: sender,
+        sentAt: now.subtract(age),
+        read: read || _readInSession.contains(id),
+        childIds: childIds,
+        attachmentCount: attachments.length,
+        status: status,
+        deadline: request?.deadline,
+      ),
+      content: ParentLetterContent(
+        body: body,
+        attachments: attachments,
+        request: request,
+        children: children,
+        thread: thread,
+      ),
+    );
+
+    return [
+      letter(
+        id: 'demo-letter-hike',
+        subject: 'Wandertag der ${DemoPersona.className}',
+        sender: _teacher(0),
+        age: const Duration(hours: 2),
+        read: false,
+        childIds: const [_lena],
+        status: ParentLetterStatus.open,
+        body:
+            'Liebe Eltern,\n\nam Freitag in zwei Wochen findet unser Wandertag '
+            'statt. Wir fahren mit dem Bus in die Rhön und sind gegen 16 Uhr '
+            'zurück. Alle Einzelheiten finden Sie im angehängten Schreiben.\n\n'
+            'Bitte geben Sie uns eine verbindliche Rückmeldung.\n\n'
+            'Viele Grüße\n${DemoPersona.teachers[0].name}',
+        attachments: const [
+          ParentLetterAttachment(
+            id: 'demo-attachment-hike',
+            fileName: 'Wandertag.pdf',
+            mimeType: 'application/pdf',
+            size: 48211,
+          ),
+        ],
+        request: ParentLetterRequest(
+          fields: const [_participation],
+          signatureRequired: true,
+          deadline: now.add(const Duration(days: 10)),
+        ),
+        children: const [
+          ParentLetterChildState(
+            childId: _lena,
+            status: ParentLetterStatus.open,
+            editable: true,
+          ),
+        ],
+      ),
+      letter(
+        id: 'demo-letter-parents-evening',
+        subject: 'Einladung zum Elternabend der 6a',
+        sender: _teacher(1),
+        age: const Duration(days: 1),
+        read: false,
+        childIds: const [_jonas],
+        status: ParentLetterStatus.open,
+        body:
+            'Liebe Eltern,\n\nhiermit lade ich Sie herzlich zum ersten '
+            'Elternabend des Schuljahres ein. Wir treffen uns am kommenden '
+            'Dienstag um 19 Uhr in Raum ${DemoPersona.rooms[0]}.\n\n'
+            'Bitte bestätigen Sie kurz den Erhalt dieser Einladung.',
+        request: const ParentLetterRequest(),
+        children: const [
+          ParentLetterChildState(
+            childId: _jonas,
+            status: ParentLetterStatus.open,
+            editable: true,
+          ),
+        ],
+      ),
+      letter(
+        id: 'demo-letter-school-festival',
+        subject: 'Schulfest: Wer kommt mit?',
+        sender: _teacher(5),
+        age: const Duration(days: 3),
+        childIds: const [_lena, _jonas],
+        status: ParentLetterStatus.open,
+        body:
+            'Liebe Eltern,\n\nfür die Planung unseres Schulfestes möchten wir '
+            'wissen, welche Kinder teilnehmen. Die Angabe können Sie bis zum '
+            'Ablauf der Frist noch ändern.\n\nWeitere Informationen: '
+            'https://www.marianum-fulda.de',
+        request: ParentLetterRequest(
+          fields: const [_participation],
+          deadline: now.add(const Duration(days: 5)),
+        ),
+        children: [
+          ParentLetterChildState(
+            childId: _lena,
+            status: ParentLetterStatus.done,
+            editable: true,
+            response: ParentLetterResponse(
+              respondedAt: now.subtract(const Duration(days: 2)),
+              respondedBy: const ParentLetterPerson(self: true),
+              answers: const [
+                ParentLetterAnswer(
+                  fieldId: 'participation',
+                  optionIds: ['yes'],
+                ),
+              ],
+            ),
+          ),
+          const ParentLetterChildState(
+            childId: _jonas,
+            status: ParentLetterStatus.open,
+            editable: true,
+          ),
+        ],
+      ),
+      letter(
+        id: 'demo-letter-reports',
+        subject: 'Zeugnisausgabe und Unterrichtsschluss',
+        sender: _teacher(3),
+        age: const Duration(days: 7),
+        childIds: const [_lena, _jonas],
+        body:
+            'Liebe Eltern,\n\nam letzten Schultag vor den Ferien endet der '
+            'Unterricht nach der dritten Stunde mit der Zeugnisausgabe. Die '
+            'Busse fahren entsprechend früher.',
+        thread: ParentLetterThread(
+          enabled: true,
+          messages: [
+            ParentLetterThreadMessage(
+              id: 'demo-thread-1',
+              author: const ParentLetterPerson(self: true),
+              body: 'Gilt das auch für die Nachmittagsbetreuung?',
+              sentAt: now.subtract(const Duration(days: 6, hours: 20)),
+            ),
+            ParentLetterThreadMessage(
+              id: 'demo-thread-2',
+              author: _teacher(3),
+              body:
+                  'Ja, die Betreuung entfällt an diesem Tag ebenfalls. Bei '
+                  'Bedarf melden Sie sich bitte im Sekretariat.',
+              sentAt: now.subtract(const Duration(days: 6, hours: 2)),
+            ),
+          ],
+        ),
+      ),
+      letter(
+        id: 'demo-letter-swimming',
+        subject: 'Einverständnis Schwimmunterricht',
+        sender: _teacher(6),
+        age: const Duration(days: 21),
+        childIds: const [_jonas],
+        status: ParentLetterStatus.done,
+        body:
+            'Liebe Eltern,\n\nim zweiten Halbjahr findet der Sportunterricht '
+            'der 6a im Hallenbad statt. Dafür benötigen wir Ihr '
+            'Einverständnis.',
+        request: const ParentLetterRequest(
+          fields: [_participation],
+          signatureRequired: true,
+        ),
+        children: [
+          ParentLetterChildState(
+            childId: _jonas,
+            status: ParentLetterStatus.done,
+            response: ParentLetterResponse(
+              respondedAt: now.subtract(const Duration(days: 20)),
+              respondedBy: const ParentLetterPerson(displayName: 'M. Hoffmann'),
+              answers: const [
+                ParentLetterAnswer(
+                  fieldId: 'participation',
+                  optionIds: ['yes'],
+                ),
+              ],
+              signed: true,
+            ),
+          ),
+        ],
+        thread: const ParentLetterThread(),
+      ),
+      letter(
+        id: 'demo-letter-ski-trip',
+        subject: 'Anmeldung zur Skifreizeit',
+        sender: _teacher(6),
+        age: const Duration(days: 35),
+        childIds: const [_lena],
+        status: ParentLetterStatus.expired,
+        body:
+            'Liebe Eltern,\n\ndie Anmeldung zur Skifreizeit der Jahrgangsstufe '
+            '10 ist ab sofort möglich. Die Plätze sind begrenzt.',
+        request: ParentLetterRequest(
+          fields: const [_participation],
+          signatureRequired: true,
+          deadline: now.subtract(const Duration(days: 14)),
+        ),
+        children: const [
+          ParentLetterChildState(
+            childId: _lena,
+            status: ParentLetterStatus.expired,
+          ),
+        ],
+        thread: const ParentLetterThread(),
+      ),
+    ];
+  }
+}

lib/api/demo/data/demo_talk.dart

@@ -1,4 +1,4 @@
-import '../../../model/account_data.dart';
+import '../../../session/session_manager.dart';
 import '../../marianumcloud/talk/chat/get_chat_response.dart';
 import '../../marianumcloud/talk/room/get_room_response.dart';
 import '../demo_persona.dart';
@@ -204,7 +204,8 @@ class DemoTalk {
         id: base + 2,
         token: token,
         ago: const Duration(days: 1, hours: 6),
-        message: 'Danke! Können wir Aufgabe 5 nächste Stunde nochmal besprechen?',
+        message:
+            'Danke! Können wir Aufgabe 5 nächste Stunde nochmal besprechen?',
       ),
       _msg(
         id: base + 3,
@@ -366,7 +367,7 @@ class DemoTalk {
   }) => _msg(
     id: id,
     token: token,
-    actor: AccountData().getUsername(),
+    actor: SessionManager().requireNextcloud().username,
     display: DemoPersona.studentName,
     ago: ago,
     message: message,

lib/api/demo/demo_mode.dart

@@ -1,4 +1,4 @@
-import '../../model/account_data.dart';
+import '../../session/session_manager.dart';
 
 /// Central switch for the client-side demo mode.
 ///
@@ -8,7 +8,7 @@ import '../../model/account_data.dart';
 /// Play reviewers and automated screenshot runs see a fully populated app
 /// without a real account and without any network dependency.
 ///
-/// The flag is persisted through [AccountData.isDemo], so a demo session
+/// The flag is persisted through [Session.isDemo], so a demo session
 /// survives cold starts exactly like a normal login. It works in release builds
 /// too — reviewers run the shipped release build.
 class DemoMode {
@@ -22,6 +22,14 @@ class DemoMode {
   static bool matches(String username) =>
       username.trim().toLowerCase().startsWith(usernamePrefix);
 
+  /// Guardian logins are passwordless, so reviewers need a fixed address that
+  /// skips the mail round-trip. Deliberately not the `demo@` prefix, which a
+  /// real e-mail address could start with.
+  static const String guardianEmail = 'demo-eltern@marianum-fulda.de';
+
+  static bool matchesGuardian(String email) =>
+      email.trim().toLowerCase() == guardianEmail;
+
   /// True while the active session is a demo session.
-  static bool get active => AccountData().isDemo;
+  static bool get active => SessionManager().isDemo;
 }

lib/api/errors/error_mapper.dart

@@ -5,6 +5,7 @@ import 'package:dio/dio.dart';
 import 'package:http/http.dart' as http;
 import 'package:nextcloud/nextcloud.dart';
 
+import '../../session/session.dart';
 import '../api_error.dart';
 import '../http_errors.dart';
 import '../marianumcloud/talk/talk_error.dart';
@@ -61,7 +62,9 @@ AppException? _dioToAppException(DioException error) {
 AppException _dynamiteToAppException(DynamiteApiException error) {
   final status = error.statusCode;
   final preview = previewBody(error.body);
-  final detail = preview.isEmpty ? 'HTTP $status' : 'HTTP $status body=$preview';
+  final detail = preview.isEmpty
+      ? 'HTTP $status'
+      : 'HTTP $status body=$preview';
   switch (status) {
     case 401:
       return AuthException.unauthorized(technicalDetails: detail);
@@ -86,6 +89,9 @@ String errorToUserMessage(Object? error, {String fallback = _defaultFallback}) {
   if (error is AppException) return error.userMessage;
 
   if (error is TalkError) return TalkException(error).userMessage;
+  if (error is NextcloudUnavailableException) {
+    return 'Diese Funktion ist mit deinem Konto nicht verfügbar.';
+  }
 
   if (error is DioException) {
     final mapped = _dioToAppException(error);
@@ -136,6 +142,7 @@ String? errorToTechnicalDetails(Object? error) {
 bool errorAllowsRetry(Object? error) {
   if (error == null) return true;
   if (error is AppException) return error.allowRetry;
+  if (error is NextcloudUnavailableException) return false;
   if (error is DioException) {
     final mapped = _dioToAppException(error);
     if (mapped != null) return mapped.allowRetry;

lib/api/marianumcloud/app_password/get_app_password.dart

@@ -2,13 +2,13 @@ import 'dart:convert';
 
 import 'package:http/http.dart' as http;
 
-import '../../../model/account_data.dart';
+import '../../../session/session_manager.dart';
 import '../../http_errors.dart';
 import '../nextcloud_ocs.dart';
 
 /// Exchanges the user's real Nextcloud password for a scoped app password via
 /// `GET /ocs/v2.php/core/getapppassword`. All subsequent Nextcloud calls then
-/// authenticate with the app password (see [AccountData.getBasicAuthHeader]),
+/// authenticate with the app password (see [NextcloudCredentials.basicAuthHeader]),
 /// which is what the push-v2 registration binds to.
 ///
 /// Must authenticate with the *real* password — an app password cannot mint
@@ -33,7 +33,9 @@ class GetAppPassword {
           // Deliberately NOT the shared Authorization value: that one prefers
           // the app password, but an app password cannot mint another one —
           // this endpoint requires the real password.
-          'Authorization': AccountData().getRealPasswordBasicAuthHeader(),
+          'Authorization': SessionManager()
+              .requireNextcloud()
+              .realPasswordBasicAuthHeader,
         },
       ),
     ))!;

lib/api/marianumcloud/cloud_users/cloud_users_actions.dart

@@ -4,8 +4,8 @@ import 'dart:typed_data';
 
 import 'package:http/http.dart' as http;
 
-import '../../../model/account_data.dart';
 import '../../../model/endpoint_data.dart';
+import '../../../session/session_manager.dart';
 import '../../errors/parse_exception.dart';
 import '../../http_errors.dart';
 import '../nextcloud_ocs.dart';
@@ -27,12 +27,12 @@ Uri _coreAvatarUri() {
   return Uri.https(endpoint.domain, '${endpoint.path}/avatar/');
 }
 
-Uri _userInfoUri() =>
-    NextcloudOcs.uri('cloud/users/${AccountData().getUsername()}');
+Uri _userInfoUri() => NextcloudOcs.uri(
+  'cloud/users/${SessionManager().requireNextcloud().username}',
+);
 
 Future<http.Response> _send(
-  Future<http.Response> Function(Uri uri, Map<String, String> headers)
-  perform,
+  Future<http.Response> Function(Uri uri, Map<String, String> headers) perform,
   Uri uri,
 ) async {
   final headers = NextcloudOcs.headers();
@@ -98,16 +98,13 @@ class GetUserInfo {
     try {
       final root = jsonDecode(response.body) as Map<String, dynamic>;
       final data =
-          (root['ocs'] as Map<String, dynamic>)['data']
-              as Map<String, dynamic>;
+          (root['ocs'] as Map<String, dynamic>)['data'] as Map<String, dynamic>;
       return CloudUserInfo(
         userId: data['id'] as String,
         displayName: (data['displayname'] as String?) ?? '',
       );
     } catch (e) {
-      throw ParseException(
-        technicalDetails: 'Cloud $uri user info parse: $e',
-      );
+      throw ParseException(technicalDetails: 'Cloud $uri user info parse: $e');
     }
   }
 }

lib/api/marianumcloud/nextcloud_ocs.dart

@@ -1,7 +1,7 @@
 import 'dart:convert';
 
-import '../../model/account_data.dart';
 import '../../model/endpoint_data.dart';
+import '../../session/session_manager.dart';
 
 /// Shared headers and URI builder for Nextcloud OCS v2 endpoints. Used by
 /// TalkApi, AutocompleteApi, FileSharingApi.
@@ -16,7 +16,7 @@ class NextcloudOcs {
   static Map<String, String> headers() => {
     'Accept': 'application/json',
     'OCS-APIRequest': 'true',
-    'Authorization': AccountData().getBasicAuthHeader(),
+    'Authorization': SessionManager().requireNextcloud().basicAuthHeader,
   };
 
   static Uri uri(String pathSuffix, {Map<String, dynamic>? queryParameters}) {

lib/api/marianumcloud/webdav/webdav_api.dart

@@ -1,7 +1,7 @@
 import 'package:nextcloud/nextcloud.dart';
 
-import '../../../model/account_data.dart';
 import '../../../model/endpoint_data.dart';
+import '../../../session/session_manager.dart';
 import '../../api_response.dart';
 
 abstract class WebdavApi<T> {
@@ -18,7 +18,7 @@ abstract class WebdavApi<T> {
   /// changes (app password minted/renewed, account switch) so it never keeps
   /// authenticating with stale credentials.
   static Future<WebDavClient> get webdav {
-    final secret = AccountData().getNextcloudSecret();
+    final secret = SessionManager().requireNextcloud().secret;
     if (_webdav == null || _webdavSecret != secret) {
       _webdavSecret = secret;
       _webdav = establishWebdavConnection();
@@ -30,13 +30,13 @@ abstract class WebdavApi<T> {
       NextcloudClient(
         Uri.parse('https://${EndpointData().nextcloud().full()}'),
         // App password preferred — with 2FA the real password is not accepted
-        // by Nextcloud at all (see AccountData.usesLoginFlow).
-        password: AccountData().getNextcloudSecret(),
-        loginName: AccountData().getUsername(),
+        // by Nextcloud at all (see NextcloudCredentials.usesLoginFlow).
+        password: SessionManager().requireNextcloud().secret,
+        loginName: SessionManager().requireNextcloud().username,
       ).webdav;
 
   /// Builds the WebDAV download URL without embedded credentials. Callers must
-  /// authenticate via the [AccountData.authHeaders] header instead.
+  /// authenticate via the [NextcloudCredentials.authHeaders] header instead.
   static String buildWebdavUrl() =>
-      'https://${EndpointData().nextcloud().full()}/remote.php/dav/files/${AccountData().getUsername()}/';
+      'https://${EndpointData().nextcloud().full()}/remote.php/dav/files/${SessionManager().requireNextcloud().username}/';
 }

lib/api/marianumconnect/auth/auth_interceptor.dart

@@ -1,12 +1,14 @@
 import 'package:dio/dio.dart';
 
-import '../../../model/account_data.dart';
+import '../../../session/session.dart';
+import '../../../session/session_manager.dart';
 import '../queries/auth_login/auth_login.dart';
 import 'device_token_name.dart';
 import 'token_storage.dart';
 
 /// Adds the bearer token to outgoing Marianum-Connect requests and, on 401,
-/// re-logs in once with the credentials in [AccountData] before retrying.
+/// renews the token once before retrying. Only password accounts can renew
+/// silently; passwordless accounts surface the 401.
 class MarianumConnectAuthInterceptor extends Interceptor {
   static const _retriedKey = 'mc_auth_retried';
 
@@ -64,6 +66,9 @@ class MarianumConnectAuthInterceptor extends Interceptor {
     }
     final refreshed = await _attemptReLogin();
     if (!refreshed) {
+      if (SessionManager().current is GuardianSession) {
+        SessionManager().reportUnauthorized();
+      }
       handler.next(err);
       return;
     }
@@ -87,11 +92,12 @@ class MarianumConnectAuthInterceptor extends Interceptor {
   }
 
   Future<bool> _performReLogin() async {
-    if (!AccountData().isPopulated()) return false;
+    final session = SessionManager().current;
+    if (session is! CredentialSession) return false;
     try {
       await _loginClient.run(
-        username: AccountData().getUsername(),
-        password: AccountData().getPassword(),
+        username: session.username,
+        password: session.password,
         tokenName: await DeviceTokenName.resolve(),
       );
       return true;

lib/api/marianumconnect/auth/session_validator.dart

@@ -1,35 +1,46 @@
 import 'dart:developer';
 
-import '../../../model/account_data.dart';
+import '../../../session/session.dart';
+import '../../../session/session_lifecycle.dart';
+import '../../../session/session_manager.dart';
 import '../../errors/auth_exception.dart';
-import '../queries/auth_logout/auth_logout.dart';
+import '../queries/auth_me/auth_me.dart';
 import '../queries/auth_verify/auth_verify.dart';
-import 'token_storage.dart';
 
-/// Background credential probe — a server-side password rotation forces a
-/// re-login on the next cold start even when the bearer token would still
-/// be accepted.
+/// Credential probe. For password accounts a server-side password rotation
+/// forces a re-login on the next cold start even when the bearer token would
+/// still be accepted; for guardians it confirms a rejected token before the
+/// session is dropped.
 class SessionValidator {
   static Future<void> probeStored({
     required Future<void> Function() onInvalidated,
   }) async {
-    if (!AccountData().isPopulated()) return;
-    // AuthVerify uses its own dio (bypassing the demo interceptor), so a demo
-    // session must be skipped here or its missing token would 401 into a logout.
-    if (AccountData().isDemo) return;
-    final username = AccountData().getUsername();
-    final password = AccountData().getPassword();
+    final session = SessionManager().current;
+    // The probes use their own dio (bypassing the demo interceptor), so a demo
+    // session must be skipped or its missing token would 401 into a logout.
+    if (session == null || session.isDemo) return;
     try {
+      switch (session) {
+        case CredentialSession(:final username, :final password):
           await AuthVerify().run(username: username, password: password);
+        case GuardianSession():
+          await AuthMe().run();
+      }
     } on AuthException catch (e) {
       if (e.statusCode != 401) return;
-      log('MC: stored credentials rejected — forcing re-login');
-      await AuthLogout().run();
-      await const MarianumConnectTokenStorage().clear();
-      await AccountData().removeData();
+      log('MC: stored session rejected — forcing re-login');
+      await SessionLifecycle.signOut(
+        notice: switch (session) {
+          CredentialSession() =>
+            'Deine Zugangsdaten wurden vom Server abgelehnt. Vermutlich '
+                'wurde dein Passwort geändert. Bitte melde dich erneut an.',
+          GuardianSession() =>
+            'Deine Anmeldung ist abgelaufen. Bitte melde dich erneut an.',
+        },
+      );
       await onInvalidated();
     } catch (e) {
-      log('MC: background credential check failed (transient): $e');
+      log('MC: background session check failed (transient): $e');
     }
   }
 }

lib/api/marianumconnect/auth/token_storage.dart

@@ -1,5 +1,8 @@
+import 'package:dio/dio.dart';
 import 'package:flutter_secure_storage/flutter_secure_storage.dart';
 
+import '../../errors/auth_exception.dart';
+
 /// `first_unlock` accessibility so the token can be read during background
 /// requests (telemetry heartbeat, push-triggered syncs) after the first device
 /// unlock following a reboot. The keychain default (`whenUnlocked`) throws
@@ -9,7 +12,7 @@ const IOSOptions _mcIosOptions = IOSOptions(
 );
 
 /// Persists the Marianum-Connect bearer token in the platform keystore. Kept
-/// separate from `AccountData` because the username/password live on (Nextcloud
+/// separate from `SessionManager` because the username/password live on (Nextcloud
 /// + MHSL still need them) while the MC token is short-lived and per-endpoint.
 class MarianumConnectTokenStorage {
   static const _tokenKey = 'mc_bearer_token';
@@ -24,6 +27,18 @@ class MarianumConnectTokenStorage {
 
   Future<String?> readToken() => _storage.read(key: _tokenKey);
 
+  /// Request options carrying the stored token, for probes that bypass the
+  /// auth interceptor. Throws [AuthException] when no token is stored.
+  Future<Options> requireBearerOptions(String caller) async {
+    final token = await readToken();
+    if (token == null || token.isEmpty) {
+      throw AuthException.unauthorized(
+        technicalDetails: '$caller: no bearer token in storage',
+      );
+    }
+    return Options(headers: {'Authorization': 'Bearer $token'});
+  }
+
   Future<String?> readTokenId() => _storage.read(key: _tokenIdKey);
 
   Future<DateTime?> readExpiresAt() async {

lib/api/marianumconnect/errors/marianumconnect_error.dart

@@ -6,6 +6,22 @@ import '../../errors/network_exception.dart';
 import '../../errors/parse_exception.dart';
 import '../../errors/server_exception.dart';
 
+/// The error code of a rejected call: the server answers either with JSON
+/// `{"error": "<code>"}` or with the plain text `Fehler: <code>` of its
+/// generic error handler.
+String? marianumConnectErrorCode(Object? body) {
+  if (body is Map) {
+    final code = body['error'];
+    return code is String ? code : null;
+  }
+  if (body is String) {
+    const prefix = 'Fehler: ';
+    return (body.startsWith(prefix) ? body.substring(prefix.length) : body)
+        .trim();
+  }
+  return null;
+}
+
 /// Converts a DioException raised against the Marianum-Connect API into one of
 /// the app's typed AppExceptions. Keeps the dio dependency out of call sites
 /// that just want to render an error message.

lib/api/marianumconnect/marianumconnect_query.dart

@@ -1,5 +1,8 @@
+import 'dart:typed_data';
+
 import 'package:dio/dio.dart';
 
+import '../errors/app_exception.dart';
 import 'errors/marianumconnect_error.dart';
 import 'marianumconnect_api.dart';
 import 'marianumconnect_endpoint.dart';
@@ -23,10 +26,14 @@ abstract class MarianumConnectQuery {
     try {
       return await body();
     } on DioException catch (e) {
-      throw mapMarianumConnectError(e);
+      throw mapError(e);
     }
   }
 
+  /// The AppException a failed call surfaces as. Query families with domain
+  /// error codes override this instead of re-implementing [guard].
+  AppException mapError(DioException error) => mapMarianumConnectError(error);
+
   /// GETs [path] and parses the JSON object body with [fromJson].
   Future<T> getObject<T>(
     String path,
@@ -55,6 +62,16 @@ abstract class MarianumConnectQuery {
         .toList();
   });
 
+  /// GETs the raw bytes of [path] (files that need the bearer token).
+  Future<Uint8List> getBytes(String path) => guard(() async {
+    final response = await dio.get<List<int>>(
+      endpoint(path),
+      options: Options(responseType: ResponseType.bytes),
+    );
+    final bytes = response.data!;
+    return bytes is Uint8List ? bytes : Uint8List.fromList(bytes);
+  });
+
   /// Formats [d] as an ISO `yyyy-MM-dd` day for MarianumConnect query params.
   String isoDate(DateTime d) =>
       '${d.year.toString().padLeft(4, '0')}-${d.month.toString().padLeft(2, '0')}-${d.day.toString().padLeft(2, '0')}';

lib/api/marianumconnect/queries/absence/absence_prefill.dart

@@ -1,10 +1,30 @@
+import '../../../errors/app_exception.dart';
 import '../../marianumconnect_query.dart';
 import 'absence_prefill_response.dart';
 
 /// GETs the absence-report form prefill (`absence/prefill`, bearer-auth).
+/// Guardians pass the [childId] the report is for; the identity then comes
+/// from that child.
 class AbsencePrefill extends MarianumConnectQuery {
   AbsencePrefill({super.dio});
 
-  Future<AbsencePrefillResponse> run() =>
-      getObject('absence/prefill', AbsencePrefillResponse.fromJson);
+  Future<AbsencePrefillResponse> run({String? childId}) => getObject(
+    'absence/prefill',
+    AbsencePrefillResponse.fromJson,
+    queryParameters: {'childId': ?childId},
+  );
+}
+
+/// The prefill of a guardian's report is missing a field the form cannot ask
+/// for: name and class come from the child and are not editable there, so an
+/// incomplete prefill would leave a locked, unsubmittable form behind.
+class AbsencePrefillIncompleteException extends AppException {
+  const AbsencePrefillIncompleteException({super.technicalDetails})
+    : super(
+        userMessage:
+            'Für dieses Kind sind in der Schulverwaltung noch nicht alle '
+            'Angaben hinterlegt, die für eine Abwesenheitsmeldung nötig sind. '
+            'Bitte wende dich an das Sekretariat.',
+        allowRetry: false,
+      );
 }

lib/api/marianumconnect/queries/absence/absence_submit.dart

@@ -3,7 +3,8 @@ import '../../marianumconnect_query.dart';
 /// Submits an absence report (`POST absence`, bearer-auth, `source=mobile`).
 /// Empty identity fields are backfilled from LDAP server-side; validation
 /// (all fields required, class must exist, no past start date, end >= start)
-/// also runs server-side and mirrors the client checks.
+/// also runs server-side and mirrors the client checks. For guardians the
+/// server takes name and class from the child given by [childId].
 class AbsenceSubmit extends MarianumConnectQuery {
   AbsenceSubmit({super.dio});
 
@@ -15,6 +16,7 @@ class AbsenceSubmit extends MarianumConnectQuery {
     required DateTime absentUntil,
     required String phone,
     required String note,
+    String? childId,
   }) => guard(() async {
     await dio.post<void>(
       endpoint('absence'),
@@ -26,6 +28,7 @@ class AbsenceSubmit extends MarianumConnectQuery {
         'absentUntil': isoDate(absentUntil),
         'phone': phone,
         'note': note,
+        'childId': ?childId,
       },
     );
   });

lib/api/marianumconnect/queries/auth_guardian/auth_guardian_request.dart

@@ -0,0 +1,60 @@
+import 'package:dio/dio.dart';
+
+import '../../../../auth_link/pending_guardian_request.dart';
+import '../../marianumconnect_api.dart';
+import '../../marianumconnect_query.dart';
+import 'guardian_login_exception.dart';
+
+class AuthGuardianRequestResponse {
+  final String requestId;
+  final DateTime expiresAt;
+  final DateTime resendAvailableAt;
+  final int codeLength;
+
+  const AuthGuardianRequestResponse({
+    required this.requestId,
+    required this.expiresAt,
+    required this.resendAvailableAt,
+    required this.codeLength,
+  });
+
+  factory AuthGuardianRequestResponse.fromJson(Map<String, dynamic> json) =>
+      AuthGuardianRequestResponse(
+        requestId: json['requestId'] as String,
+        expiresAt: DateTime.parse(json['expiresAt'] as String),
+        resendAvailableAt: DateTime.parse(json['resendAvailableAt'] as String),
+        codeLength:
+            json['codeLength'] as int? ??
+            PendingGuardianRequest.defaultCodeLength,
+      );
+}
+
+/// Starts a passwordless guardian login: the server mails a code and a link.
+/// An unknown address is reported as such (`email_not_registered`) instead of
+/// being answered like a known one — a deliberate trade: without it guardians
+/// wait for a mail that never arrives. Registered addresses are therefore
+/// enumerable; keep that in mind when changing the server contract.
+class AuthGuardianRequest extends MarianumConnectQuery {
+  AuthGuardianRequest({Dio? dio})
+    : super(dio: dio ?? MarianumConnectApi.plainDio());
+
+  Future<AuthGuardianRequestResponse> run({
+    required String email,
+    required String deviceChallenge,
+    required String tokenName,
+  }) async {
+    try {
+      final response = await dio.post<Map<String, dynamic>>(
+        endpoint('auth/guardian/request'),
+        data: {
+          'email': email,
+          'deviceChallenge': deviceChallenge,
+          'tokenName': tokenName,
+        },
+      );
+      return AuthGuardianRequestResponse.fromJson(response.data!);
+    } on DioException catch (e) {
+      throw GuardianLoginException.fromDio(e, verifying: false);
+    }
+  }
+}

lib/api/marianumconnect/queries/auth_guardian/auth_guardian_verify.dart

@@ -0,0 +1,51 @@
+import 'package:dio/dio.dart';
+
+import '../../auth/token_storage.dart';
+import '../../marianumconnect_api.dart';
+import '../../marianumconnect_query.dart';
+import '../auth_login/auth_login_response.dart';
+import 'guardian_login_exception.dart';
+
+/// Completes a guardian login with the mailed code or link token and stores
+/// the issued bearer token.
+class AuthGuardianVerify extends MarianumConnectQuery {
+  final MarianumConnectTokenStorage _tokenStorage;
+
+  AuthGuardianVerify({
+    MarianumConnectTokenStorage tokenStorage =
+        const MarianumConnectTokenStorage(),
+    Dio? dio,
+  }) : _tokenStorage = tokenStorage,
+       super(dio: dio ?? MarianumConnectApi.plainDio());
+
+  Future<AuthLoginResponse> run({
+    required String requestId,
+    required String deviceVerifier,
+    required String tokenName,
+    String? code,
+    String? linkToken,
+  }) async {
+    assert((code == null) != (linkToken == null));
+    try {
+      final response = await dio.post<Map<String, dynamic>>(
+        endpoint('auth/guardian/verify'),
+        data: {
+          'requestId': requestId,
+          'deviceVerifier': deviceVerifier,
+          'tokenName': tokenName,
+          'code': ?code,
+          'linkToken': ?linkToken,
+        },
+      );
+      final payload = AuthLoginResponse.fromJson(response.data!);
+      await _tokenStorage.write(
+        token: payload.token,
+        tokenId: payload.tokenId,
+        expiresAt: payload.expiresAt,
+      );
+      return payload;
+    } on DioException catch (e) {
+      throw GuardianLoginException.fromDio(e);
+    }
+  }
+}

lib/api/marianumconnect/queries/auth_guardian/guardian_login_exception.dart

@@ -0,0 +1,120 @@
+import 'package:dio/dio.dart';
+
+import '../../../errors/app_exception.dart';
+import '../../errors/marianumconnect_error.dart';
+
+enum GuardianLoginError {
+  invalidRequest,
+  emailNotRegistered,
+  accountDisabled,
+  invalidCode,
+  deviceMismatch,
+  requestConsumed,
+  requestExpired,
+  tooManyAttempts,
+  rateLimited,
+  unsupportedServer,
+}
+
+/// A rejected guardian login step with the reason the server reported.
+class GuardianLoginException extends AppException {
+  final GuardianLoginError error;
+  final int? attemptsLeft;
+
+  const GuardianLoginException(
+    this.error, {
+    required super.userMessage,
+    this.attemptsLeft,
+    super.technicalDetails,
+  }) : super(allowRetry: false);
+
+  /// Maps a failed guardian auth call. Only 4xx answers that carry a guardian
+  /// login reason become [GuardianLoginException]; everything else keeps the
+  /// generic MarianumConnect mapping (network, 5xx, …).
+  ///
+  /// [verifying] false marks the e-mail step, where no code exists yet: a bare
+  /// 401 (reverse proxy, gateway) must not be reported as a wrong code there.
+  static AppException fromDio(DioException e, {bool verifying = true}) {
+    final response = e.response;
+    final status = response?.statusCode;
+    if (status == null || status < 400 || status >= 500) {
+      return mapMarianumConnectError(e);
+    }
+    final (code, attemptsLeft) = _parseBody(response!.data);
+    final error = _errorFor(code, status, verifying: verifying);
+    if (error == null) return mapMarianumConnectError(e);
+    return GuardianLoginException(
+      error,
+      attemptsLeft: attemptsLeft,
+      userMessage: messageFor(error, attemptsLeft: attemptsLeft),
+      technicalDetails: 'MC $status: ${response.data}',
+    );
+  }
+
+  static String messageFor(
+    GuardianLoginError error, {
+    int? attemptsLeft,
+  }) => switch (error) {
+    GuardianLoginError.invalidRequest =>
+      'Bitte gib eine gültige E-Mail-Adresse ein.',
+    GuardianLoginError.emailNotRegistered =>
+      'Unter dieser E-Mail-Adresse ist kein Eltern-Zugang hinterlegt. '
+          'Bitte prüfe, ob die korrekte Adresse verwendet wurde. Bitte wende dich an das Sekretariat, '
+          'wenn du nicht weißt, welche Adresse für dich registriert ist.',
+    GuardianLoginError.accountDisabled =>
+      'Dieser Eltern-Zugang ist derzeit deaktiviert. Bitte wende dich an '
+          'das Sekretariat.',
+    GuardianLoginError.invalidCode =>
+      attemptsLeft == null
+          ? 'Der Code ist falsch.'
+          : 'Der Code ist falsch. Noch $attemptsLeft '
+                '${attemptsLeft == 1 ? 'Versuch' : 'Versuche'}.',
+    GuardianLoginError.deviceMismatch =>
+      'Dieser Anmeldelink wurde auf einem anderen Gerät angefordert. '
+          'Bitte gib stattdessen den Code aus der E-Mail ein.',
+    GuardianLoginError.requestConsumed =>
+      'Diese Anmeldung wurde bereits verwendet. Bitte fordere einen neuen '
+          'Code an.',
+    GuardianLoginError.requestExpired =>
+      'Der Code ist abgelaufen. Bitte fordere einen neuen an.',
+    GuardianLoginError.tooManyAttempts =>
+      'Zu viele Fehlversuche. Bitte fordere einen neuen Code an.',
+    GuardianLoginError.rateLimited =>
+      'Zu viele Anfragen. Bitte warte einige Stunden und versuche es '
+          'erneut.',
+    GuardianLoginError.unsupportedServer =>
+      'Die Eltern-Anmeldung ist auf diesem Server noch nicht verfügbar. '
+          'Bitte versuche es später erneut.',
+  };
+
+  static (String?, int?) _parseBody(Object? data) {
+    final attempts = data is Map ? data['attemptsLeft'] : null;
+    return (marianumConnectErrorCode(data), attempts is int ? attempts : null);
+  }
+
+  static GuardianLoginError? _errorFor(
+    String? code,
+    int status, {
+    required bool verifying,
+  }) => switch (code) {
+        'invalid_request' => GuardianLoginError.invalidRequest,
+        'email_not_registered' => GuardianLoginError.emailNotRegistered,
+        'account_disabled' => GuardianLoginError.accountDisabled,
+        'invalid_code' => GuardianLoginError.invalidCode,
+        'device_mismatch' => GuardianLoginError.deviceMismatch,
+        'request_consumed' => GuardianLoginError.requestConsumed,
+        'request_expired' => GuardianLoginError.requestExpired,
+        'too_many_attempts' => GuardianLoginError.tooManyAttempts,
+        _ => switch (status) {
+          401 when verifying => GuardianLoginError.invalidCode,
+          // The server names an unknown address explicitly
+          // (`email_not_registered`); a bare 404/405 means the endpoint itself
+          // is missing, i.e. a server version without guardian login.
+          404 || 405 => GuardianLoginError.unsupportedServer,
+          409 => GuardianLoginError.requestConsumed,
+          410 => GuardianLoginError.requestExpired,
+          429 => GuardianLoginError.rateLimited,
+          _ => null,
+        },
+      };
+}

lib/api/marianumconnect/queries/auth_me/auth_me.dart

@@ -0,0 +1,30 @@
+import 'package:dio/dio.dart';
+
+import '../../../errors/auth_exception.dart';
+import '../../auth/token_storage.dart';
+import '../../marianumconnect_api.dart';
+import '../../marianumconnect_query.dart';
+
+/// Probes that the stored bearer token is still accepted. Used for accounts
+/// without a password (guardians), whose token cannot be renewed silently.
+///
+/// Bypasses the shared dio singleton so the auth interceptor does not react
+/// to the 401 this probe is meant to observe.
+class AuthMe extends MarianumConnectQuery {
+  final MarianumConnectTokenStorage _tokenStorage;
+
+  AuthMe({
+    MarianumConnectTokenStorage tokenStorage =
+        const MarianumConnectTokenStorage(),
+    Dio? dio,
+  }) : _tokenStorage = tokenStorage,
+       super(dio: dio ?? MarianumConnectApi.plainDio());
+
+  /// Throws [AuthException] when the token is missing or rejected.
+  Future<void> run() async {
+    final options = await _tokenStorage.requireBearerOptions('AuthMe');
+    return guard(() async {
+      await dio.get<void>(endpoint('auth/me'), options: options);
+    });
+  }
+}

lib/api/marianumconnect/queries/auth_verify/auth_verify.dart

@@ -29,17 +29,12 @@ class AuthVerify extends MarianumConnectQuery {
     required String username,
     required String password,
   }) async {
-    final token = await _tokenStorage.readToken();
-    if (token == null || token.isEmpty) {
-      throw AuthException.unauthorized(
-        technicalDetails: 'AuthVerify: no bearer token in storage',
-      );
-    }
+    final options = await _tokenStorage.requireBearerOptions('AuthVerify');
     return guard(() async {
       await dio.post<void>(
         endpoint('auth/verify'),
         data: {'username': username, 'password': password},
-        options: Options(headers: {'Authorization': 'Bearer $token'}),
+        options: options,
       );
     });
   }

lib/api/marianumconnect/queries/get_capabilities/get_capabilities_response.dart

@@ -1,5 +1,7 @@
 import 'package:json_annotation/json_annotation.dart';
 
+import 'guardian_child.dart';
+
 part 'get_capabilities_response.g.dart';
 
 /// Slimmed-down capability flags the mobile UI gates features on. The backend
@@ -23,16 +25,21 @@ class CapabilitiesResponse {
 
   final int? timetableFutureDays;
 
-  /// LDAP user type ('TEACHER' | 'STUDENT' | 'STAFF'). Null when the backend
-  /// predates the field or has no LDAP record for the user.
+  /// User type ('TEACHER' | 'STUDENT' | 'STAFF' | 'PARENT'). Null when the
+  /// backend predates the field or has no record for the user.
   final String? userType;
 
+  /// Students linked to a guardian account; empty for everyone else.
+  @JsonKey(defaultValue: <GuardianChild>[])
+  final List<GuardianChild> children;
+
   CapabilitiesResponse({
     required this.viewForeignTimetables,
     required this.pushNotifications,
     this.timetablePastDays,
     this.timetableFutureDays,
     this.userType,
+    this.children = const [],
   });
 
   factory CapabilitiesResponse.fromJson(Map<String, dynamic> json) =>

lib/api/marianumconnect/queries/get_capabilities/get_capabilities_response.g.dart

@@ -14,6 +14,11 @@ CapabilitiesResponse _$CapabilitiesResponseFromJson(
   timetablePastDays: (json['timetablePastDays'] as num?)?.toInt(),
   timetableFutureDays: (json['timetableFutureDays'] as num?)?.toInt(),
   userType: json['userType'] as String?,
+  children:
+      (json['children'] as List<dynamic>?)
+          ?.map((e) => GuardianChild.fromJson(e as Map<String, dynamic>))
+          .toList() ??
+      [],
 );
 
 Map<String, dynamic> _$CapabilitiesResponseToJson(
@@ -24,4 +29,5 @@ Map<String, dynamic> _$CapabilitiesResponseToJson(
   'timetablePastDays': instance.timetablePastDays,
   'timetableFutureDays': instance.timetableFutureDays,
   'userType': instance.userType,
+  'children': instance.children,
 };

lib/api/marianumconnect/queries/get_capabilities/guardian_child.dart

@@ -0,0 +1,23 @@
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+part 'guardian_child.freezed.dart';
+part 'guardian_child.g.dart';
+
+/// A student linked to the signed-in guardian. [id] is an opaque server id,
+/// not a WebUntis id.
+@freezed
+abstract class GuardianChild with _$GuardianChild {
+  const GuardianChild._();
+
+  const factory GuardianChild({
+    required String id,
+    required String firstName,
+    required String lastName,
+    @Default('') String className,
+  }) = _GuardianChild;
+
+  factory GuardianChild.fromJson(Map<String, Object?> json) =>
+      _$GuardianChildFromJson(json);
+
+  String get displayName => '$firstName $lastName'.trim();
+}

lib/api/marianumconnect/queries/get_capabilities/guardian_child.freezed.dart

@@ -0,0 +1,294 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// coverage:ignore-file
+// ignore_for_file: type=lint, type=warning, deprecated_member_use, deprecated_member_use_from_same_package
+// ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
+
+part of 'guardian_child.dart';
+
+// **************************************************************************
+// FreezedGenerator
+// **************************************************************************
+
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// dart format off
+T _$identity<T>(T value) => value;
+
+/// @nodoc
+mixin _$GuardianChild {
+
+ String get id; String get firstName; String get lastName; String get className;
+/// Create a copy of GuardianChild
+/// with the given fields replaced by the non-null parameter values.
+@JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+$GuardianChildCopyWith<GuardianChild> get copyWith => _$GuardianChildCopyWithImpl<GuardianChild>(this as GuardianChild, _$identity);
+
+  /// Serializes this GuardianChild to a JSON map.
+  Map<String, dynamic> toJson();
+
+
+@override
+bool operator ==(Object other) {
+  final _this = this as GuardianChild;
+  return identical(this, other) || (other.runtimeType == runtimeType&&other is GuardianChild&&(identical(other.id, _this.id) || other.id == _this.id)&&(identical(other.firstName, _this.firstName) || other.firstName == _this.firstName)&&(identical(other.lastName, _this.lastName) || other.lastName == _this.lastName)&&(identical(other.className, _this.className) || other.className == _this.className));
+}
+
+@JsonKey(includeFromJson: false, includeToJson: false)
+@override
+int get hashCode {
+  final _this = this as GuardianChild;
+  return Object.hash(runtimeType,_this.id,_this.firstName,_this.lastName,_this.className);
+}
+
+@override
+String toString() {
+  final _this = this as GuardianChild;
+  return 'GuardianChild(id: ${_this.id}, firstName: ${_this.firstName}, lastName: ${_this.lastName}, className: ${_this.className})';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class $GuardianChildCopyWith<$Res>  {
+  factory $GuardianChildCopyWith(GuardianChild value, $Res Function(GuardianChild) _then) = _$GuardianChildCopyWithImpl;
+@useResult
+$Res call({
+ String id, String firstName, String lastName, String className
+});
+
+
+
+
+}
+/// @nodoc
+class _$GuardianChildCopyWithImpl<$Res>
+    implements $GuardianChildCopyWith<$Res> {
+  _$GuardianChildCopyWithImpl(this._self, this._then);
+
+  final GuardianChild _self;
+  final $Res Function(GuardianChild) _then;
+
+/// Create a copy of GuardianChild
+/// with the given fields replaced by the non-null parameter values.
+@pragma('vm:prefer-inline') @override $Res call({Object? id = null,Object? firstName = null,Object? lastName = null,Object? className = null,}) {
+  return _then(GuardianChild(
+id: null == id ? _self.id : id // ignore: cast_nullable_to_non_nullable
+as String,firstName: null == firstName ? _self.firstName : firstName // ignore: cast_nullable_to_non_nullable
+as String,lastName: null == lastName ? _self.lastName : lastName // ignore: cast_nullable_to_non_nullable
+as String,className: null == className ? _self.className : className // ignore: cast_nullable_to_non_nullable
+as String,
+  ));
+}
+
+}
+
+
+/// Adds pattern-matching-related methods to [GuardianChild].
+extension GuardianChildPatterns on GuardianChild {
+/// A variant of `map` that fallback to returning `orElse`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeMap<TResult extends Object?>(TResult Function( _GuardianChild value)?  $default,{required TResult orElse(),}){
+final _that = this;
+switch (_that) {
+case _GuardianChild() when $default != null:
+return $default(_that);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// Callbacks receives the raw object, upcasted.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case final Subclass2 value:
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult map<TResult extends Object?>(TResult Function( _GuardianChild value)  $default,){
+final _that = this;
+switch (_that) {
+case _GuardianChild():
+return $default(_that);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `map` that fallback to returning `null`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? mapOrNull<TResult extends Object?>(TResult? Function( _GuardianChild value)?  $default,){
+final _that = this;
+switch (_that) {
+case _GuardianChild() when $default != null:
+return $default(_that);case _:
+  return null;
+
+}
+}
+/// A variant of `when` that fallback to an `orElse` callback.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeWhen<TResult extends Object?>(TResult Function( String id,  String firstName,  String lastName,  String className)?  $default,{required TResult orElse(),}) {final _that = this;
+switch (_that) {
+case _GuardianChild() when $default != null:
+return $default(_that.id,_that.firstName,_that.lastName,_that.className);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// As opposed to `map`, this offers destructuring.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case Subclass2(:final field2):
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult when<TResult extends Object?>(TResult Function( String id,  String firstName,  String lastName,  String className)  $default,) {final _that = this;
+switch (_that) {
+case _GuardianChild():
+return $default(_that.id,_that.firstName,_that.lastName,_that.className);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `when` that fallback to returning `null`
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? Function( String id,  String firstName,  String lastName,  String className)?  $default,) {final _that = this;
+switch (_that) {
+case _GuardianChild() when $default != null:
+return $default(_that.id,_that.firstName,_that.lastName,_that.className);case _:
+  return null;
+
+}
+}
+
+}
+
+/// @nodoc
+@JsonSerializable()
+
+class _GuardianChild extends GuardianChild {
+  const _GuardianChild({required this.id, required this.firstName, required this.lastName, this.className = ''}): super._();
+  factory _GuardianChild.fromJson(Map<String, dynamic> json) => _$GuardianChildFromJson(json);
+
+@override final  String id;
+@override final  String firstName;
+@override final  String lastName;
+@override@JsonKey() final  String className;
+
+/// Create a copy of GuardianChild
+/// with the given fields replaced by the non-null parameter values.
+@override @JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+_$GuardianChildCopyWith<_GuardianChild> get copyWith => __$GuardianChildCopyWithImpl<_GuardianChild>(this, _$identity);
+
+@override
+Map<String, dynamic> toJson() {
+  return _$GuardianChildToJson(this, );
+}
+
+@override
+bool operator ==(Object other) {
+    return identical(this, other) || (other.runtimeType == runtimeType&&other is _GuardianChild&&(identical(other.id, id) || other.id == id)&&(identical(other.firstName, firstName) || other.firstName == firstName)&&(identical(other.lastName, lastName) || other.lastName == lastName)&&(identical(other.className, className) || other.className == className));
+}
+
+@JsonKey(includeFromJson: false, includeToJson: false)
+@override
+int get hashCode {
+    return Object.hash(runtimeType,id,firstName,lastName,className);
+}
+
+@override
+String toString() {
+    return 'GuardianChild(id: $id, firstName: $firstName, lastName: $lastName, className: $className)';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class _$GuardianChildCopyWith<$Res> implements $GuardianChildCopyWith<$Res> {
+  factory _$GuardianChildCopyWith(_GuardianChild value, $Res Function(_GuardianChild) _then) = __$GuardianChildCopyWithImpl;
+@override @useResult
+$Res call({
+ String id, String firstName, String lastName, String className
+});
+
+
+
+
+}
+/// @nodoc
+class __$GuardianChildCopyWithImpl<$Res>
+    implements _$GuardianChildCopyWith<$Res> {
+  __$GuardianChildCopyWithImpl(this._self, this._then);
+
+  final _GuardianChild _self;
+  final $Res Function(_GuardianChild) _then;
+
+/// Create a copy of GuardianChild
+/// with the given fields replaced by the non-null parameter values.
+@override @pragma('vm:prefer-inline') $Res call({Object? id = null,Object? firstName = null,Object? lastName = null,Object? className = null,}) {
+  return _then(_GuardianChild(
+id: null == id ? _self.id : id // ignore: cast_nullable_to_non_nullable
+as String,firstName: null == firstName ? _self.firstName : firstName // ignore: cast_nullable_to_non_nullable
+as String,lastName: null == lastName ? _self.lastName : lastName // ignore: cast_nullable_to_non_nullable
+as String,className: null == className ? _self.className : className // ignore: cast_nullable_to_non_nullable
+as String,
+  ));
+}
+
+
+}
+
+// dart format on

lib/api/marianumconnect/queries/get_capabilities/guardian_child.g.dart

@@ -0,0 +1,23 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'guardian_child.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+_GuardianChild _$GuardianChildFromJson(Map<String, dynamic> json) =>
+    _GuardianChild(
+      id: json['id'] as String,
+      firstName: json['firstName'] as String,
+      lastName: json['lastName'] as String,
+      className: json['className'] as String? ?? '',
+    );
+
+Map<String, dynamic> _$GuardianChildToJson(_GuardianChild instance) =>
+    <String, dynamic>{
+      'id': instance.id,
+      'firstName': instance.firstName,
+      'lastName': instance.lastName,
+      'className': instance.className,
+    };

lib/api/marianumconnect/queries/get_newsletter_file/get_newsletter_file.dart

@@ -1,7 +1,5 @@
 import 'dart:typed_data';
 
-import 'package:dio/dio.dart';
-
 import '../../marianumconnect_query.dart';
 
 /// Downloads the raw PDF bytes of a Marianum Message from
@@ -15,11 +13,6 @@ class GetNewsletterFile extends MarianumConnectQuery {
 
   GetNewsletterFile(this.id, {super.dio});
 
-  Future<Uint8List> run() => guard(() async {
-    final response = await dio.get<List<int>>(
-      endpoint('newsletter/${Uri.encodeComponent(id)}/file'),
-      options: Options(responseType: ResponseType.bytes),
-    );
-    return Uint8List.fromList(response.data!);
-  });
+  Future<Uint8List> run() =>
+      getBytes('newsletter/${Uri.encodeComponent(id)}/file');
 }

lib/api/marianumconnect/queries/get_ticker_page_file/get_ticker_page_file.dart

@@ -1,7 +1,5 @@
 import 'dart:typed_data';
 
-import 'package:dio/dio.dart';
-
 import '../../marianumconnect_query.dart';
 
 /// Downloads the raw bytes of a PROXIED_FILE ticker page from
@@ -15,11 +13,6 @@ class GetTickerPageFile extends MarianumConnectQuery {
 
   GetTickerPageFile(this.slug, {super.dio});
 
-  Future<Uint8List> run() => guard(() async {
-    final response = await dio.get<List<int>>(
-      endpoint('ticker/pages/${Uri.encodeComponent(slug)}/file'),
-      options: Options(responseType: ResponseType.bytes),
-    );
-    return Uint8List.fromList(response.data!);
-  });
+  Future<Uint8List> run() =>
+      getBytes('ticker/pages/${Uri.encodeComponent(slug)}/file');
 }

lib/api/marianumconnect/queries/parent_letters/get_parent_letter.dart

@@ -0,0 +1,9 @@
+import 'parent_letter_models.dart';
+import 'parent_letter_query.dart';
+
+class GetParentLetter extends ParentLetterQuery {
+  GetParentLetter({super.dio});
+
+  Future<ParentLetterDetail> run(String letterId) =>
+      getObject(letterPath(letterId), ParentLetterDetail.fromJson);
+}

lib/api/marianumconnect/queries/parent_letters/get_parent_letter_attachment.dart

@@ -0,0 +1,14 @@
+import 'dart:typed_data';
+
+import 'parent_letter_query.dart';
+
+class GetParentLetterAttachment extends ParentLetterQuery {
+  GetParentLetterAttachment({super.dio});
+
+  Future<Uint8List> run({
+    required String letterId,
+    required String attachmentId,
+  }) => getBytes(
+    letterPath(letterId, '/attachments/${Uri.encodeComponent(attachmentId)}'),
+  );
+}

lib/api/marianumconnect/queries/parent_letters/get_parent_letters.dart

@@ -0,0 +1,16 @@
+import 'parent_letter_models.dart';
+import 'parent_letter_query.dart';
+
+/// `GET parent-letters`: the guardian's inbox across all children, newest
+/// first. [before] continues after the given letter (keyset paging).
+class GetParentLetters extends ParentLetterQuery {
+  static const int pageSize = 50;
+
+  GetParentLetters({super.dio});
+
+  Future<ParentLetterListResponse> run({String? before}) => getObject(
+    'parent-letters',
+    ParentLetterListResponse.fromJson,
+    queryParameters: {'limit': pageSize, 'before': ?before},
+  );
+}

lib/api/marianumconnect/queries/parent_letters/mark_parent_letter_read.dart

@@ -0,0 +1,11 @@
+import 'parent_letter_query.dart';
+
+/// `POST parent-letters/{id}/read`: marks the letter and its thread as read
+/// for this guardian. Idempotent.
+class MarkParentLetterRead extends ParentLetterQuery {
+  MarkParentLetterRead({super.dio});
+
+  Future<void> run(String letterId) => guard(() async {
+    await dio.post<void>(endpoint(letterPath(letterId, '/read')));
+  });
+}

lib/api/marianumconnect/queries/parent_letters/parent_letter_exception.dart

@@ -0,0 +1,90 @@
+import 'package:dio/dio.dart';
+
+import '../../../errors/app_exception.dart';
+import '../../errors/marianumconnect_error.dart';
+
+enum ParentLetterError {
+  guardianRequired,
+  letterNotFound,
+  childNotFound,
+  attachmentNotFound,
+  invalidAnswers,
+  signatureRequired,
+  responseFinal,
+  deadlinePassed,
+  threadDisabled,
+  invalidRequest,
+}
+
+/// A parent-letter call the server rejected with a domain reason.
+class ParentLetterException extends AppException {
+  final ParentLetterError error;
+
+  const ParentLetterException(
+    this.error, {
+    required super.userMessage,
+    super.technicalDetails,
+  }) : super(allowRetry: false);
+
+  /// Only 4xx answers with a parent-letter reason become a
+  /// [ParentLetterException]; everything else (network, 401, 5xx) keeps the
+  /// generic MarianumConnect mapping.
+  static AppException fromDio(DioException e) {
+    final response = e.response;
+    final status = response?.statusCode;
+    if (status == null || status < 400 || status >= 500 || status == 401) {
+      return mapMarianumConnectError(e);
+    }
+    final error = _errorFor(marianumConnectErrorCode(response!.data), status);
+    if (error == null) return mapMarianumConnectError(e);
+    return ParentLetterException(
+      error,
+      userMessage: messageFor(error),
+      technicalDetails: 'MC $status: ${response.data}',
+    );
+  }
+
+  static String messageFor(ParentLetterError error) => switch (error) {
+    ParentLetterError.guardianRequired =>
+      'Elternbriefe sind nur mit einem Eltern-Konto verfügbar.',
+    ParentLetterError.letterNotFound =>
+      'Dieser Elternbrief ist nicht mehr verfügbar.',
+    ParentLetterError.childNotFound =>
+      'Dieser Elternbrief betrifft das ausgewählte Kind nicht.',
+    ParentLetterError.attachmentNotFound =>
+      'Der Anhang ist nicht mehr verfügbar.',
+    ParentLetterError.invalidAnswers =>
+      'Die Rückmeldung ist unvollständig. Bitte prüfe deine Angaben.',
+    ParentLetterError.signatureRequired =>
+      'Für diese Rückmeldung wird eine Unterschrift benötigt.',
+    ParentLetterError.responseFinal =>
+      'Die Rückmeldung wurde bereits endgültig abgegeben und kann nicht mehr '
+          'geändert werden.',
+    ParentLetterError.deadlinePassed =>
+      'Die Frist für diese Rückmeldung ist abgelaufen.',
+    ParentLetterError.threadDisabled =>
+      'Auf diesen Elternbrief kann nicht geantwortet werden.',
+    ParentLetterError.invalidRequest =>
+      'Die Anfrage konnte nicht verarbeitet werden.',
+  };
+
+  static ParentLetterError? _errorFor(String? code, int status) =>
+      switch (code) {
+        'guardian_required' => ParentLetterError.guardianRequired,
+        'letter_not_found' => ParentLetterError.letterNotFound,
+        'child_not_found' => ParentLetterError.childNotFound,
+        'attachment_not_found' => ParentLetterError.attachmentNotFound,
+        'invalid_answers' => ParentLetterError.invalidAnswers,
+        'signature_required' => ParentLetterError.signatureRequired,
+        'response_final' => ParentLetterError.responseFinal,
+        'deadline_passed' => ParentLetterError.deadlinePassed,
+        'thread_disabled' => ParentLetterError.threadDisabled,
+        'invalid_request' => ParentLetterError.invalidRequest,
+        _ => switch (status) {
+          404 => ParentLetterError.letterNotFound,
+          409 => ParentLetterError.responseFinal,
+          410 => ParentLetterError.deadlinePassed,
+          _ => null,
+        },
+      };
+}

lib/api/marianumconnect/queries/parent_letters/parent_letter_models.dart

@@ -0,0 +1,226 @@
+import 'package:flutter/foundation.dart';
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+part 'parent_letter_models.freezed.dart';
+part 'parent_letter_models.g.dart';
+
+enum ParentLetterStatus { info, open, done, expired }
+
+enum ParentLetterFieldType {
+  @JsonValue('single_choice')
+  singleChoice,
+  unknown,
+}
+
+/// Sender, thread author or responding guardian. [self] marks the signed-in
+/// guardian.
+@freezed
+abstract class ParentLetterPerson with _$ParentLetterPerson {
+  const factory ParentLetterPerson({
+    @Default('') String displayName,
+    @Default(false) bool self,
+  }) = _ParentLetterPerson;
+
+  factory ParentLetterPerson.fromJson(Map<String, dynamic> json) =>
+      _$ParentLetterPersonFromJson(json);
+}
+
+/// Inbox entry from `GET parent-letters`. [childIds] are the opaque guardian
+/// child ids from `me/capabilities`.
+@freezed
+abstract class ParentLetterSummary with _$ParentLetterSummary {
+  const factory ParentLetterSummary({
+    required String id,
+    @Default('') String subject,
+    @Default('') String preview,
+    @Default(ParentLetterPerson()) ParentLetterPerson sender,
+    required DateTime sentAt,
+    DateTime? editedAt,
+    @Default(true) bool read,
+    @Default([]) List<String> childIds,
+    @Default(0) int attachmentCount,
+    @JsonKey(unknownEnumValue: ParentLetterStatus.info)
+    @Default(ParentLetterStatus.info)
+    ParentLetterStatus status,
+    DateTime? deadline,
+  }) = _ParentLetterSummary;
+
+  factory ParentLetterSummary.fromJson(Map<String, dynamic> json) =>
+      _$ParentLetterSummaryFromJson(json);
+}
+
+@freezed
+abstract class ParentLetterListResponse with _$ParentLetterListResponse {
+  const factory ParentLetterListResponse({
+    @Default([]) List<ParentLetterSummary> items,
+    @Default(false) bool hasMore,
+    @Default(0) int unreadCount,
+    @Default(0) int openCount,
+  }) = _ParentLetterListResponse;
+
+  factory ParentLetterListResponse.fromJson(Map<String, dynamic> json) =>
+      _$ParentLetterListResponseFromJson(json);
+}
+
+@freezed
+abstract class ParentLetterAttachment with _$ParentLetterAttachment {
+  const factory ParentLetterAttachment({
+    required String id,
+    @Default('') String fileName,
+    @Default('') String mimeType,
+    @Default(0) int size,
+  }) = _ParentLetterAttachment;
+
+  factory ParentLetterAttachment.fromJson(Map<String, dynamic> json) =>
+      _$ParentLetterAttachmentFromJson(json);
+}
+
+@freezed
+abstract class ParentLetterOption with _$ParentLetterOption {
+  const factory ParentLetterOption({
+    required String id,
+    @Default('') String label,
+  }) = _ParentLetterOption;
+
+  factory ParentLetterOption.fromJson(Map<String, dynamic> json) =>
+      _$ParentLetterOptionFromJson(json);
+}
+
+@freezed
+abstract class ParentLetterField with _$ParentLetterField {
+  const factory ParentLetterField({
+    required String id,
+    @JsonKey(unknownEnumValue: ParentLetterFieldType.unknown)
+    @Default(ParentLetterFieldType.unknown)
+    ParentLetterFieldType type,
+    @Default('') String label,
+    @JsonKey(name: 'required') @Default(false) bool isRequired,
+    @Default([]) List<ParentLetterOption> options,
+  }) = _ParentLetterField;
+
+  factory ParentLetterField.fromJson(Map<String, dynamic> json) =>
+      _$ParentLetterFieldFromJson(json);
+}
+
+/// What the sender asks for. No fields and no signature means a plain
+/// acknowledgement.
+@freezed
+abstract class ParentLetterRequest with _$ParentLetterRequest {
+  const factory ParentLetterRequest({
+    @Default([]) List<ParentLetterField> fields,
+    @Default(false) bool signatureRequired,
+    DateTime? deadline,
+  }) = _ParentLetterRequest;
+
+  factory ParentLetterRequest.fromJson(Map<String, dynamic> json) =>
+      _$ParentLetterRequestFromJson(json);
+}
+
+@freezed
+abstract class ParentLetterAnswer with _$ParentLetterAnswer {
+  const factory ParentLetterAnswer({
+    required String fieldId,
+    @Default([]) List<String> optionIds,
+    String? text,
+  }) = _ParentLetterAnswer;
+
+  factory ParentLetterAnswer.fromJson(Map<String, dynamic> json) =>
+      _$ParentLetterAnswerFromJson(json);
+}
+
+@freezed
+abstract class ParentLetterResponse with _$ParentLetterResponse {
+  const factory ParentLetterResponse({
+    DateTime? respondedAt,
+    @Default(ParentLetterPerson()) ParentLetterPerson respondedBy,
+    @Default([]) List<ParentLetterAnswer> answers,
+    @Default(false) bool signed,
+  }) = _ParentLetterResponse;
+
+  factory ParentLetterResponse.fromJson(Map<String, dynamic> json) =>
+      _$ParentLetterResponseFromJson(json);
+}
+
+/// Per-child state of a letter. [editable] is the server's verdict on whether
+/// this guardian may (re)submit right now.
+@freezed
+abstract class ParentLetterChildState with _$ParentLetterChildState {
+  const factory ParentLetterChildState({
+    required String childId,
+    @JsonKey(unknownEnumValue: ParentLetterStatus.info)
+    @Default(ParentLetterStatus.info)
+    ParentLetterStatus status,
+    @Default(false) bool editable,
+    ParentLetterResponse? response,
+  }) = _ParentLetterChildState;
+
+  factory ParentLetterChildState.fromJson(Map<String, dynamic> json) =>
+      _$ParentLetterChildStateFromJson(json);
+}
+
+@freezed
+abstract class ParentLetterThreadMessage with _$ParentLetterThreadMessage {
+  const factory ParentLetterThreadMessage({
+    required String id,
+    @Default(ParentLetterPerson()) ParentLetterPerson author,
+    @Default('') String body,
+    required DateTime sentAt,
+  }) = _ParentLetterThreadMessage;
+
+  factory ParentLetterThreadMessage.fromJson(Map<String, dynamic> json) =>
+      _$ParentLetterThreadMessageFromJson(json);
+}
+
+@freezed
+abstract class ParentLetterThread with _$ParentLetterThread {
+  const factory ParentLetterThread({
+    @Default(false) bool enabled,
+    @Default([]) List<ParentLetterThreadMessage> messages,
+  }) = _ParentLetterThread;
+
+  factory ParentLetterThread.fromJson(Map<String, dynamic> json) =>
+      _$ParentLetterThreadFromJson(json);
+}
+
+/// The detail-only part of `GET parent-letters/{id}`.
+@freezed
+abstract class ParentLetterContent with _$ParentLetterContent {
+  const factory ParentLetterContent({
+    @Default('') String body,
+    @Default([]) List<ParentLetterAttachment> attachments,
+    ParentLetterRequest? request,
+    @Default([]) List<ParentLetterChildState> children,
+    @Default(ParentLetterThread()) ParentLetterThread thread,
+  }) = _ParentLetterContent;
+
+  factory ParentLetterContent.fromJson(Map<String, dynamic> json) =>
+      _$ParentLetterContentFromJson(json);
+}
+
+/// A full letter. The server sends the inbox fields and the detail fields in
+/// one flat object; they are parsed into [summary] and [content] so the inbox
+/// entry can be replaced from a detail answer without copying fields.
+@immutable
+class ParentLetterDetail {
+  final ParentLetterSummary summary;
+  final ParentLetterContent content;
+
+  const ParentLetterDetail({required this.summary, required this.content});
+
+  factory ParentLetterDetail.fromJson(Map<String, dynamic> json) =>
+      ParentLetterDetail(
+        summary: ParentLetterSummary.fromJson(json),
+        content: ParentLetterContent.fromJson(json),
+      );
+
+  Map<String, dynamic> toJson() => {...summary.toJson(), ...content.toJson()};
+
+  @override
+  bool operator ==(Object other) =>
+      other is ParentLetterDetail &&
+      other.summary == summary &&
+      other.content == content;
+
+  @override
+  int get hashCode => Object.hash(summary, content);
+}

lib/api/marianumconnect/queries/parent_letters/parent_letter_models.g.dart

@@ -0,0 +1,331 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'parent_letter_models.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+_ParentLetterPerson _$ParentLetterPersonFromJson(Map<String, dynamic> json) =>
+    _ParentLetterPerson(
+      displayName: json['displayName'] as String? ?? '',
+      self: json['self'] as bool? ?? false,
+    );
+
+Map<String, dynamic> _$ParentLetterPersonToJson(_ParentLetterPerson instance) =>
+    <String, dynamic>{
+      'displayName': instance.displayName,
+      'self': instance.self,
+    };
+
+_ParentLetterSummary _$ParentLetterSummaryFromJson(Map<String, dynamic> json) =>
+    _ParentLetterSummary(
+      id: json['id'] as String,
+      subject: json['subject'] as String? ?? '',
+      preview: json['preview'] as String? ?? '',
+      sender: json['sender'] == null
+          ? const ParentLetterPerson()
+          : ParentLetterPerson.fromJson(json['sender'] as Map<String, dynamic>),
+      sentAt: DateTime.parse(json['sentAt'] as String),
+      editedAt: json['editedAt'] == null
+          ? null
+          : DateTime.parse(json['editedAt'] as String),
+      read: json['read'] as bool? ?? true,
+      childIds:
+          (json['childIds'] as List<dynamic>?)
+              ?.map((e) => e as String)
+              .toList() ??
+          const [],
+      attachmentCount: (json['attachmentCount'] as num?)?.toInt() ?? 0,
+      status:
+          $enumDecodeNullable(
+            _$ParentLetterStatusEnumMap,
+            json['status'],
+            unknownValue: ParentLetterStatus.info,
+          ) ??
+          ParentLetterStatus.info,
+      deadline: json['deadline'] == null
+          ? null
+          : DateTime.parse(json['deadline'] as String),
+    );
+
+Map<String, dynamic> _$ParentLetterSummaryToJson(
+  _ParentLetterSummary instance,
+) => <String, dynamic>{
+  'id': instance.id,
+  'subject': instance.subject,
+  'preview': instance.preview,
+  'sender': instance.sender,
+  'sentAt': instance.sentAt.toIso8601String(),
+  'editedAt': instance.editedAt?.toIso8601String(),
+  'read': instance.read,
+  'childIds': instance.childIds,
+  'attachmentCount': instance.attachmentCount,
+  'status': _$ParentLetterStatusEnumMap[instance.status]!,
+  'deadline': instance.deadline?.toIso8601String(),
+};
+
+const _$ParentLetterStatusEnumMap = {
+  ParentLetterStatus.info: 'info',
+  ParentLetterStatus.open: 'open',
+  ParentLetterStatus.done: 'done',
+  ParentLetterStatus.expired: 'expired',
+};
+
+_ParentLetterListResponse _$ParentLetterListResponseFromJson(
+  Map<String, dynamic> json,
+) => _ParentLetterListResponse(
+  items:
+      (json['items'] as List<dynamic>?)
+          ?.map((e) => ParentLetterSummary.fromJson(e as Map<String, dynamic>))
+          .toList() ??
+      const [],
+  hasMore: json['hasMore'] as bool? ?? false,
+  unreadCount: (json['unreadCount'] as num?)?.toInt() ?? 0,
+  openCount: (json['openCount'] as num?)?.toInt() ?? 0,
+);
+
+Map<String, dynamic> _$ParentLetterListResponseToJson(
+  _ParentLetterListResponse instance,
+) => <String, dynamic>{
+  'items': instance.items,
+  'hasMore': instance.hasMore,
+  'unreadCount': instance.unreadCount,
+  'openCount': instance.openCount,
+};
+
+_ParentLetterAttachment _$ParentLetterAttachmentFromJson(
+  Map<String, dynamic> json,
+) => _ParentLetterAttachment(
+  id: json['id'] as String,
+  fileName: json['fileName'] as String? ?? '',
+  mimeType: json['mimeType'] as String? ?? '',
+  size: (json['size'] as num?)?.toInt() ?? 0,
+);
+
+Map<String, dynamic> _$ParentLetterAttachmentToJson(
+  _ParentLetterAttachment instance,
+) => <String, dynamic>{
+  'id': instance.id,
+  'fileName': instance.fileName,
+  'mimeType': instance.mimeType,
+  'size': instance.size,
+};
+
+_ParentLetterOption _$ParentLetterOptionFromJson(Map<String, dynamic> json) =>
+    _ParentLetterOption(
+      id: json['id'] as String,
+      label: json['label'] as String? ?? '',
+    );
+
+Map<String, dynamic> _$ParentLetterOptionToJson(_ParentLetterOption instance) =>
+    <String, dynamic>{'id': instance.id, 'label': instance.label};
+
+_ParentLetterField _$ParentLetterFieldFromJson(Map<String, dynamic> json) =>
+    _ParentLetterField(
+      id: json['id'] as String,
+      type:
+          $enumDecodeNullable(
+            _$ParentLetterFieldTypeEnumMap,
+            json['type'],
+            unknownValue: ParentLetterFieldType.unknown,
+          ) ??
+          ParentLetterFieldType.unknown,
+      label: json['label'] as String? ?? '',
+      isRequired: json['required'] as bool? ?? false,
+      options:
+          (json['options'] as List<dynamic>?)
+              ?.map(
+                (e) => ParentLetterOption.fromJson(e as Map<String, dynamic>),
+              )
+              .toList() ??
+          const [],
+    );
+
+Map<String, dynamic> _$ParentLetterFieldToJson(_ParentLetterField instance) =>
+    <String, dynamic>{
+      'id': instance.id,
+      'type': _$ParentLetterFieldTypeEnumMap[instance.type]!,
+      'label': instance.label,
+      'required': instance.isRequired,
+      'options': instance.options,
+    };
+
+const _$ParentLetterFieldTypeEnumMap = {
+  ParentLetterFieldType.singleChoice: 'single_choice',
+  ParentLetterFieldType.unknown: 'unknown',
+};
+
+_ParentLetterRequest _$ParentLetterRequestFromJson(Map<String, dynamic> json) =>
+    _ParentLetterRequest(
+      fields:
+          (json['fields'] as List<dynamic>?)
+              ?.map(
+                (e) => ParentLetterField.fromJson(e as Map<String, dynamic>),
+              )
+              .toList() ??
+          const [],
+      signatureRequired: json['signatureRequired'] as bool? ?? false,
+      deadline: json['deadline'] == null
+          ? null
+          : DateTime.parse(json['deadline'] as String),
+    );
+
+Map<String, dynamic> _$ParentLetterRequestToJson(
+  _ParentLetterRequest instance,
+) => <String, dynamic>{
+  'fields': instance.fields,
+  'signatureRequired': instance.signatureRequired,
+  'deadline': instance.deadline?.toIso8601String(),
+};
+
+_ParentLetterAnswer _$ParentLetterAnswerFromJson(Map<String, dynamic> json) =>
+    _ParentLetterAnswer(
+      fieldId: json['fieldId'] as String,
+      optionIds:
+          (json['optionIds'] as List<dynamic>?)
+              ?.map((e) => e as String)
+              .toList() ??
+          const [],
+      text: json['text'] as String?,
+    );
+
+Map<String, dynamic> _$ParentLetterAnswerToJson(_ParentLetterAnswer instance) =>
+    <String, dynamic>{
+      'fieldId': instance.fieldId,
+      'optionIds': instance.optionIds,
+      'text': instance.text,
+    };
+
+_ParentLetterResponse _$ParentLetterResponseFromJson(
+  Map<String, dynamic> json,
+) => _ParentLetterResponse(
+  respondedAt: json['respondedAt'] == null
+      ? null
+      : DateTime.parse(json['respondedAt'] as String),
+  respondedBy: json['respondedBy'] == null
+      ? const ParentLetterPerson()
+      : ParentLetterPerson.fromJson(
+          json['respondedBy'] as Map<String, dynamic>,
+        ),
+  answers:
+      (json['answers'] as List<dynamic>?)
+          ?.map((e) => ParentLetterAnswer.fromJson(e as Map<String, dynamic>))
+          .toList() ??
+      const [],
+  signed: json['signed'] as bool? ?? false,
+);
+
+Map<String, dynamic> _$ParentLetterResponseToJson(
+  _ParentLetterResponse instance,
+) => <String, dynamic>{
+  'respondedAt': instance.respondedAt?.toIso8601String(),
+  'respondedBy': instance.respondedBy,
+  'answers': instance.answers,
+  'signed': instance.signed,
+};
+
+_ParentLetterChildState _$ParentLetterChildStateFromJson(
+  Map<String, dynamic> json,
+) => _ParentLetterChildState(
+  childId: json['childId'] as String,
+  status:
+      $enumDecodeNullable(
+        _$ParentLetterStatusEnumMap,
+        json['status'],
+        unknownValue: ParentLetterStatus.info,
+      ) ??
+      ParentLetterStatus.info,
+  editable: json['editable'] as bool? ?? false,
+  response: json['response'] == null
+      ? null
+      : ParentLetterResponse.fromJson(json['response'] as Map<String, dynamic>),
+);
+
+Map<String, dynamic> _$ParentLetterChildStateToJson(
+  _ParentLetterChildState instance,
+) => <String, dynamic>{
+  'childId': instance.childId,
+  'status': _$ParentLetterStatusEnumMap[instance.status]!,
+  'editable': instance.editable,
+  'response': instance.response,
+};
+
+_ParentLetterThreadMessage _$ParentLetterThreadMessageFromJson(
+  Map<String, dynamic> json,
+) => _ParentLetterThreadMessage(
+  id: json['id'] as String,
+  author: json['author'] == null
+      ? const ParentLetterPerson()
+      : ParentLetterPerson.fromJson(json['author'] as Map<String, dynamic>),
+  body: json['body'] as String? ?? '',
+  sentAt: DateTime.parse(json['sentAt'] as String),
+);
+
+Map<String, dynamic> _$ParentLetterThreadMessageToJson(
+  _ParentLetterThreadMessage instance,
+) => <String, dynamic>{
+  'id': instance.id,
+  'author': instance.author,
+  'body': instance.body,
+  'sentAt': instance.sentAt.toIso8601String(),
+};
+
+_ParentLetterThread _$ParentLetterThreadFromJson(Map<String, dynamic> json) =>
+    _ParentLetterThread(
+      enabled: json['enabled'] as bool? ?? false,
+      messages:
+          (json['messages'] as List<dynamic>?)
+              ?.map(
+                (e) => ParentLetterThreadMessage.fromJson(
+                  e as Map<String, dynamic>,
+                ),
+              )
+              .toList() ??
+          const [],
+    );
+
+Map<String, dynamic> _$ParentLetterThreadToJson(_ParentLetterThread instance) =>
+    <String, dynamic>{
+      'enabled': instance.enabled,
+      'messages': instance.messages,
+    };
+
+_ParentLetterContent _$ParentLetterContentFromJson(Map<String, dynamic> json) =>
+    _ParentLetterContent(
+      body: json['body'] as String? ?? '',
+      attachments:
+          (json['attachments'] as List<dynamic>?)
+              ?.map(
+                (e) =>
+                    ParentLetterAttachment.fromJson(e as Map<String, dynamic>),
+              )
+              .toList() ??
+          const [],
+      request: json['request'] == null
+          ? null
+          : ParentLetterRequest.fromJson(
+              json['request'] as Map<String, dynamic>,
+            ),
+      children:
+          (json['children'] as List<dynamic>?)
+              ?.map(
+                (e) =>
+                    ParentLetterChildState.fromJson(e as Map<String, dynamic>),
+              )
+              .toList() ??
+          const [],
+      thread: json['thread'] == null
+          ? const ParentLetterThread()
+          : ParentLetterThread.fromJson(json['thread'] as Map<String, dynamic>),
+    );
+
+Map<String, dynamic> _$ParentLetterContentToJson(
+  _ParentLetterContent instance,
+) => <String, dynamic>{
+  'body': instance.body,
+  'attachments': instance.attachments,
+  'request': instance.request,
+  'children': instance.children,
+  'thread': instance.thread,
+};

lib/api/marianumconnect/queries/parent_letters/parent_letter_query.dart

@@ -0,0 +1,18 @@
+import 'package:dio/dio.dart';
+
+import '../../../errors/app_exception.dart';
+import '../../marianumconnect_query.dart';
+import 'parent_letter_exception.dart';
+
+/// Base for the parent-letter calls: domain rejections surface as
+/// [ParentLetterException].
+abstract class ParentLetterQuery extends MarianumConnectQuery {
+  ParentLetterQuery({super.dio});
+
+  String letterPath(String letterId, [String suffix = '']) =>
+      'parent-letters/${Uri.encodeComponent(letterId)}$suffix';
+
+  @override
+  AppException mapError(DioException error) =>
+      ParentLetterException.fromDio(error);
+}

lib/api/marianumconnect/queries/parent_letters/post_parent_letter_thread_message.dart

@@ -0,0 +1,20 @@
+import 'parent_letter_models.dart';
+import 'parent_letter_query.dart';
+
+/// `POST parent-letters/{id}/thread`. [clientMessageId] makes a retry
+/// idempotent on the server.
+class PostParentLetterThreadMessage extends ParentLetterQuery {
+  PostParentLetterThreadMessage({super.dio});
+
+  Future<ParentLetterThreadMessage> run({
+    required String letterId,
+    required String body,
+    required String clientMessageId,
+  }) => guard(() async {
+    final response = await dio.post<Map<String, dynamic>>(
+      endpoint(letterPath(letterId, '/thread')),
+      data: {'body': body, 'clientMessageId': clientMessageId},
+    );
+    return ParentLetterThreadMessage.fromJson(response.data!);
+  });
+}

lib/api/marianumconnect/queries/parent_letters/submit_parent_letter_response.dart

@@ -0,0 +1,34 @@
+import 'dart:convert';
+import 'dart:typed_data';
+
+import 'parent_letter_models.dart';
+import 'parent_letter_query.dart';
+
+/// `PUT parent-letters/{id}/responses/{childId}`: creates or (while editable)
+/// replaces the response for one child. Answers with the updated letter.
+class SubmitParentLetterResponse extends ParentLetterQuery {
+  SubmitParentLetterResponse({super.dio});
+
+  Future<ParentLetterDetail> run({
+    required String letterId,
+    required String childId,
+    required List<ParentLetterAnswer> answers,
+    Uint8List? signaturePng,
+  }) => guard(() async {
+    final response = await dio.put<Map<String, dynamic>>(
+      endpoint(
+        letterPath(letterId, '/responses/${Uri.encodeComponent(childId)}'),
+      ),
+      data: {
+        'answers': [
+          for (final answer in answers)
+            {'fieldId': answer.fieldId, 'optionIds': answer.optionIds},
+        ],
+        'signaturePng': signaturePng == null
+            ? null
+            : base64Encode(signaturePng),
+      },
+    );
+    return ParentLetterDetail.fromJson(response.data!);
+  });
+}

lib/api/marianumconnect/queries/push_device_register/push_device_register.dart

@@ -1,16 +1,18 @@
 import '../../marianumconnect_query.dart';
 
 /// Registers (upserts) this device's push subscription with MarianumConnect via
-/// `PUT /api/mobile/v1/me/push-device`. The backend verifies the Nextcloud
-/// device-identifier signature, stores the routing metadata and starts
-/// forwarding Nextcloud pushes to this device's FCM token. Responds 204.
+/// `PUT /api/mobile/v1/me/push-device`. For Nextcloud registrations the backend
+/// verifies the device-identifier signature and forwards Nextcloud pushes to
+/// this device's FCM token; `direct` registrations (accounts without
+/// Nextcloud) carry no signature and only receive MarianumConnect pushes.
+/// Responds 204.
 class PushDeviceRegister extends MarianumConnectQuery {
   PushDeviceRegister({super.dio});
 
   Future<void> run({
     required String deviceIdentifier,
-    required String deviceIdentifierSignature,
-    required String userPublicKey,
+    String? deviceIdentifierSignature,
+    String? userPublicKey,
     required String pushToken,
     required String platform,
     required String registrationType,
@@ -20,12 +22,13 @@ class PushDeviceRegister extends MarianumConnectQuery {
       endpoint('me/push-device'),
       data: {
         'deviceIdentifier': deviceIdentifier,
-        'deviceIdentifierSignature': deviceIdentifierSignature,
-        'userPublicKey': userPublicKey,
+        'deviceIdentifierSignature': ?deviceIdentifierSignature,
+        'userPublicKey': ?userPublicKey,
         'pushToken': pushToken,
         'platform': platform,
         // 'general' | 'talk' — the backend derives the NC hash comparison
         // value from it (general = sha512(token), talk = sha512(token+'#talk')).
+        // 'direct' — no Nextcloud subscription behind it.
         'registrationType': registrationType,
         'appVersion': ?appVersion,
       },

lib/api/marianumconnect/queries/telemetry_heartbeat/telemetry_device_id.dart

@@ -1,7 +1,7 @@
-import 'dart:math';
-
 import 'package:flutter_secure_storage/flutter_secure_storage.dart';
 
+import '../../../../utils/random_id.dart';
+
 /// A stable, anonymous per-install identifier for telemetry. Generated once on
 /// first use (128 bits from a cryptographic RNG) and persisted in the secure
 /// keystore, so a device stays a single row across password rotations and FCM
@@ -21,15 +21,9 @@ class TelemetryDeviceId {
       _cached = existing;
       return existing;
     }
-    final generated = _generate();
+    final generated = randomHexId();
     await _storage.write(key: _key, value: generated);
     _cached = generated;
     return generated;
   }
-
-  static String _generate() {
-    final random = Random.secure();
-    final bytes = List<int>.generate(16, (_) => random.nextInt(256));
-    return bytes.map((b) => b.toRadixString(16).padLeft(2, '0')).join();
-  }
 }

lib/api/marianumconnect/queries/timetable_custom_events/custom_events_migration.dart

@@ -2,8 +2,8 @@ import 'dart:developer';
 
 import 'package:localstore/localstore.dart';
 
-import '../../../../model/account_data.dart';
-import '../../../demo/demo_mode.dart';
+import '../../../../session/session.dart';
+import '../../../../session/session_manager.dart';
 import '../../../mhsl/custom_timetable_event/get/get_custom_timetable_event.dart';
 import '../../../mhsl/custom_timetable_event/get/get_custom_timetable_event_params.dart';
 import '../../../mhsl/custom_timetable_event/remove/remove_custom_timetable_event.dart';
@@ -28,12 +28,15 @@ class CustomEventsMigration {
   const CustomEventsMigration._();
 
   static Future<void> runOnce() async {
-    if (DemoMode.active) return;
+    // Guardians never had MHSL events; only password accounts can derive the
+    // legacy identity.
+    final session = SessionManager().current;
+    if (session is! CredentialSession || session.isDemo) return;
     if (await _isDone()) return;
 
     try {
       final response = await GetCustomTimetableEvent(
-        GetCustomTimetableEventParams(AccountData().getUserSecret()),
+        GetCustomTimetableEventParams(session.legacyUserSecret),
       ).run();
 
       for (final event in response.events) {
@@ -44,7 +47,9 @@ class CustomEventsMigration {
       }
 
       await _markDone();
-      log('Custom events migration: moved ${response.events.length} event(s) to Marianum-Connect.');
+      log(
+        'Custom events migration: moved ${response.events.length} event(s) to Marianum-Connect.',
+      );
     } catch (e) {
       // Leave the flag unset so the next launch retries; the delete-after-post
       // above keeps a partial run duplicate-free.

lib/api/marianumconnect/queries/timetable_get_child_week/timetable_get_child_week.dart

@@ -0,0 +1,18 @@
+import '../../marianumconnect_query.dart';
+import '../timetable_get_week/timetable_get_week_response.dart';
+
+/// Fetches the weekly timetable of a guardian's child from
+/// `timetable/child/{childId}`. Same response shape as `timetable/me`.
+class TimetableGetChildWeek extends MarianumConnectQuery {
+  TimetableGetChildWeek({super.dio});
+
+  Future<TimetableGetWeekResponse> run({
+    required String childId,
+    required DateTime from,
+    required DateTime until,
+  }) => getObject(
+    'timetable/child/${Uri.encodeComponent(childId)}',
+    TimetableGetWeekResponse.fromJson,
+    queryParameters: {'from': isoDate(from), 'until': isoDate(until)},
+  );
+}

lib/app.dart

@@ -11,11 +11,14 @@ import 'api/marianumconnect/queries/telemetry_heartbeat/telemetry_heartbeat.dart
 import 'main.dart';
 import 'model/data_cleaner.dart';
 import 'notification/notification_controller.dart';
+import 'notification/notification_service.dart';
 import 'notification/notification_tasks.dart';
 import 'push/push_registration.dart';
 import 'push/push_tap_router.dart';
 import 'routing/app_routes.dart';
+import 'session/session_manager.dart';
 import 'share_intent/share_intent_listener.dart';
+import 'state/app/infrastructure/loadable_state/loadable_state.dart';
 import 'state/app/modules/app_modules.dart';
 import 'state/app/modules/breaker/bloc/breaker_bloc.dart';
 import 'state/app/modules/capabilities/bloc/capabilities_cubit.dart';
@@ -23,13 +26,16 @@ import 'state/app/modules/chat_list/bloc/chat_list_bloc.dart';
 import 'state/app/modules/settings/bloc/settings_cubit.dart';
 import 'state/app/modules/timetable/bloc/timetable_bloc.dart';
 import 'state/app/modules/timetable/bloc/timetable_state.dart';
+import 'state/app/modules/timetable/policy/timetable_policy.dart';
 import 'storage/settings.dart' as model;
 import 'utils/debouncer.dart';
 import 'utils/haptics.dart';
 import 'view/pages/overhang.dart';
 import 'widget/breaker/breaker.dart';
+import 'widget/info_dialog.dart';
 import 'widget_data/widget_navigation.dart';
 import 'widget_data/widget_publisher.dart';
+import 'widget_data/widget_sync.dart';
 
 class App extends StatefulWidget {
   const App({super.key});
@@ -40,7 +46,6 @@ class App extends StatefulWidget {
 
 class _AppState extends State<App> with WidgetsBindingObserver {
   late Timer _updateTimings;
-  StreamSubscription<dynamic>? _timetableWidgetSync;
   StreamSubscription<RemoteMessage>? _onMessageSub;
   StreamSubscription<RemoteMessage>? _onMessageOpenedAppSub;
   StreamSubscription<String>? _fcmTokenRefreshSub;
@@ -115,18 +120,11 @@ class _AppState extends State<App> with WidgetsBindingObserver {
     }
   }
 
-  void _onPushTapPending() {
-    final token = PushTapRouter.pendingChatToken.value;
-    if (token == null || !mounted) return;
-    PushTapRouter.pendingChatToken.value = null;
-    NotificationTasks.navigateToTalk(context, chatToken: token);
-  }
-
-  void _onNewsletterTapPending() {
-    final id = PushTapRouter.pendingNewsletterId.value;
-    if (id == null || !mounted) return;
-    PushTapRouter.pendingNewsletterId.value = null;
-    AppRoutes.openNewsletterById(context, id: id);
+  void _onPushTargetPending() {
+    final target = PushTapRouter.pendingTarget.value;
+    if (target == null || !mounted) return;
+    PushTapRouter.pendingTarget.value = null;
+    NotificationTasks.openPushTarget(context, target);
   }
 
   Future<void> _handlePendingWidgetNavigation() async {
@@ -142,12 +140,43 @@ class _AppState extends State<App> with WidgetsBindingObserver {
     AppRoutes.goToTab(context, Modules.timetable);
   }
 
+  /// Mirrors the primary plan into the home-screen widget without waiting
+  /// for the periodic background refresh.
+  void _publishWidget(TimetableBloc bloc) {
+    final data = bloc.state.data;
+    if (!mounted || data is! TimetableState) return;
+    if (WidgetSync.encodeSubject(bloc.subject) == null) return;
+    unawaited(
+      WidgetPublisher.publishFromBlocState(
+        data,
+        subject: bloc.subject,
+        settings: context.read<SettingsCubit>().val(),
+        showClassInsteadOfTeacher: TimetablePolicy.resolve(
+          subject: bloc.subject,
+          capabilities: context.read<CapabilitiesCubit>().state,
+        ).showClassInsteadOfTeacher,
+      ),
+    );
+  }
+
   void _handlePendingShare() {
     if (!mounted) return;
     final share = ShareIntentListener.pending.value;
     if (share == null) return;
     // A second share would otherwise leave the previous share-flow page
     // on top with stale (already-cleared) file paths.
+    // Sharing targets Talk chats and Files folders only.
+    final session = SessionManager().current;
+    if (!AppModule.isAvailableFor(Modules.talk, session) &&
+        !AppModule.isAvailableFor(Modules.files, session)) {
+      ShareIntentListener.instance.clear();
+      InfoDialog.show(
+        context,
+        'Mit diesem Konto können keine Inhalte in die App geteilt werden.',
+        title: 'Teilen nicht möglich',
+      );
+      return;
+    }
     final navigator = Navigator.of(context);
     if (navigator.canPop()) {
       navigator.popUntil((route) => route.isFirst || route is PopupRoute);
@@ -168,37 +197,9 @@ class _AppState extends State<App> with WidgetsBindingObserver {
       if (!mounted) return;
       context.read<BreakerBloc>().refresh();
       context.read<ChatListBloc>().refresh();
-      // Re-mounts on every login, so this also covers post-logout state reset.
-      final timetable = context.read<TimetableBloc>();
-      timetable.refresh();
-      // Mirror BLoC updates into the home-screen widget without waiting
-      // for the periodic background refresh.
-      final settingsCubit = context.read<SettingsCubit>();
-      final capabilitiesCubit = context.read<CapabilitiesCubit>();
-      _timetableWidgetSync?.cancel();
-      _timetableWidgetSync = timetable.stream.listen((state) {
-        final data = state.data;
-        if (data is TimetableState && !state.isLoading) {
-          unawaited(
-            WidgetPublisher.publishFromBlocState(
-              data,
-              settings: settingsCubit.val(),
-              isTeacher: capabilitiesCubit.isTeacher,
-            ),
-          );
-        }
-      });
-      // Initial publish in case hydrated storage already has data.
-      final initialData = timetable.state.data;
-      if (initialData is TimetableState) {
-        unawaited(
-          WidgetPublisher.publishFromBlocState(
-            initialData,
-            settings: settingsCubit.val(),
-            isTeacher: capabilitiesCubit.isTeacher,
-          ),
-        );
-      }
+      // Initial publish in case hydrated storage already has data. No refresh
+      // needed: PrimaryTimetableScope hands out a freshly loading bloc.
+      _publishWidget(context.read<TimetableBloc>());
       unawaited(_handlePendingWidgetNavigation());
       ShareIntentListener.instance.attach();
       ShareIntentListener.pending.addListener(_handlePendingShare);
@@ -227,8 +228,12 @@ class _AppState extends State<App> with WidgetsBindingObserver {
 
     // Android renders pushes locally, so a tap arrives via the local
     // notifications callback (PushTapRouter) rather than onMessageOpenedApp.
-    PushTapRouter.pendingChatToken.addListener(_onPushTapPending);
-    PushTapRouter.pendingNewsletterId.addListener(_onNewsletterTapPending);
+    PushTapRouter.pendingTarget.addListener(_onPushTargetPending);
+    unawaited(
+      PushTapRouter.handleAppLaunch(
+        NotificationService().flutterLocalNotificationsPlugin,
+      ),
+    );
 
     _onMessageSub = FirebaseMessaging.onMessage.listen((message) {
       if (!mounted) return;
@@ -254,12 +259,10 @@ class _AppState extends State<App> with WidgetsBindingObserver {
   @override
   void dispose() {
     _updateTimings.cancel();
-    _timetableWidgetSync?.cancel();
     _onMessageSub?.cancel();
     _onMessageOpenedAppSub?.cancel();
     _fcmTokenRefreshSub?.cancel();
-    PushTapRouter.pendingChatToken.removeListener(_onPushTapPending);
-    PushTapRouter.pendingNewsletterId.removeListener(_onNewsletterTapPending);
+    PushTapRouter.pendingTarget.removeListener(_onPushTargetPending);
     ShareIntentListener.pending.removeListener(_handlePendingShare);
     ShareIntentListener.instance.detach();
     Main.bottomNavigator.removeListener(_onTabControllerChanged);
@@ -268,7 +271,24 @@ class _AppState extends State<App> with WidgetsBindingObserver {
   }
 
   @override
-  Widget build(
+  Widget build(BuildContext context) =>
+      BlocListener<TimetableBloc, LoadableState<TimetableState>>(
+        // Also follows a swapped instance (child switch), unlike a manual
+        // stream subscription.
+        listenWhen: (_, state) => !state.isLoading,
+        // A week change emits several times (week, prefetched neighbours);
+        // one widget reload for the burst is enough.
+        listener: (_, _) => Debouncer.debounce(
+          'widgetPublish',
+          const Duration(milliseconds: 500),
+          () {
+            if (mounted) _publishWidget(context.read<TimetableBloc>());
+          },
+        ),
+        child: _buildShell(context),
+      );
+
+  Widget _buildShell(
     BuildContext context,
   ) => BlocBuilder<SettingsCubit, model.Settings>(
     builder: (context, _) {

lib/auth_link/device_binding.dart

@@ -0,0 +1,22 @@
+import 'dart:convert';
+import 'dart:math';
+
+import 'package:crypto/crypto.dart';
+
+/// Binds a guardian login request to the device that started it (PKCE-style):
+/// the request carries only [challengeFor] of a secret that never leaves the
+/// device, verification sends the secret itself. A mail link opened on another
+/// device therefore cannot complete the login.
+abstract final class DeviceBinding {
+  static String generateSecret([Random? random]) {
+    final rng = random ?? Random.secure();
+    final bytes = List<int>.generate(32, (_) => rng.nextInt(256));
+    return _base64UrlNoPad(bytes);
+  }
+
+  static String challengeFor(String secret) =>
+      _base64UrlNoPad(sha256.convert(utf8.encode(secret)).bytes);
+
+  static String _base64UrlNoPad(List<int> bytes) =>
+      base64Url.encode(bytes).replaceAll('=', '');
+}

lib/auth_link/guardian_link_listener.dart

@@ -0,0 +1,45 @@
+import 'package:app_links/app_links.dart';
+import 'package:flutter/foundation.dart';
+
+import 'guardian_login_link.dart';
+
+/// Bridges incoming App Links / Universal Links into [pending]; the login
+/// screen consumes it. Mirrors ShareIntentListener: [initialize] reads the
+/// cold-start link before `runApp` and then follows links while running.
+///
+/// Links are kept raw and parsed on consumption: the endpoint setting the
+/// link is checked against is only applied once the app is built.
+class GuardianLinkListener {
+  GuardianLinkListener._();
+  static final GuardianLinkListener instance = GuardianLinkListener._();
+
+  static final ValueNotifier<Uri?> pending = ValueNotifier(null);
+
+  final AppLinks _appLinks = AppLinks();
+  bool _listening = false;
+
+  Future<void> initialize() async {
+    try {
+      final initial = await _appLinks.getInitialLink();
+      if (initial != null) _publish(initial);
+    } catch (e) {
+      debugPrint('GuardianLinkListener.initialize failed: $e');
+    }
+    if (_listening) return;
+    _listening = true;
+    // Kept for the whole process lifetime; links can arrive at any time.
+    _appLinks.uriLinkStream.listen(
+      _publish,
+      onError: (Object e) => debugPrint('GuardianLinkListener error: $e'),
+    );
+  }
+
+  // Cheap pre-filter; the host check against the active endpoint happens in
+  // GuardianLoginLink.parse.
+  void _publish(Uri uri) {
+    if (!uri.path.endsWith(GuardianLoginLink.path)) return;
+    pending.value = uri;
+  }
+
+  static void clear() => pending.value = null;
+}

lib/auth_link/guardian_login_link.dart

@@ -0,0 +1,26 @@
+/// A sign-in link from the guardian login mail
+/// (`https://<connect-host>/app/guardian-login?rid=…&lt=…`).
+class GuardianLoginLink {
+  static const path = '/app/guardian-login';
+
+  final String requestId;
+  final String linkToken;
+
+  const GuardianLoginLink({required this.requestId, required this.linkToken});
+
+  /// Parses [uri] if it is a guardian login link for the server at [apiBase].
+  /// Links of another server (e.g. live link while the app points at beta)
+  /// are rejected: the request only exists on the server that sent the mail.
+  static GuardianLoginLink? parse(Uri uri, {required Uri apiBase}) {
+    if (uri.scheme != 'https' || uri.host != apiBase.host) return null;
+    final basePath = apiBase.path.endsWith('/')
+        ? apiBase.path.substring(0, apiBase.path.length - 1)
+        : apiBase.path;
+    if (uri.path != '$basePath$path') return null;
+    final requestId = uri.queryParameters['rid'];
+    final linkToken = uri.queryParameters['lt'];
+    if (requestId == null || requestId.isEmpty) return null;
+    if (linkToken == null || linkToken.isEmpty) return null;
+    return GuardianLoginLink(requestId: requestId, linkToken: linkToken);
+  }
+}

lib/auth_link/pending_guardian_request.dart

@@ -0,0 +1,83 @@
+import 'dart:convert';
+
+import 'package:flutter_secure_storage/flutter_secure_storage.dart';
+
+/// A guardian login request waiting for its code or link. Persisted because
+/// Android often kills the app while the user reads the mail.
+class PendingGuardianRequest {
+  static const int defaultCodeLength = 6;
+
+  final String requestId;
+  final String email;
+  final String deviceSecret;
+  final DateTime expiresAt;
+  final DateTime resendAvailableAt;
+  final int codeLength;
+
+  const PendingGuardianRequest({
+    required this.requestId,
+    required this.email,
+    required this.deviceSecret,
+    required this.expiresAt,
+    required this.resendAvailableAt,
+    this.codeLength = defaultCodeLength,
+  });
+
+  bool isExpired(DateTime now) => !now.isBefore(expiresAt);
+
+  Map<String, Object> toJson() => {
+    'requestId': requestId,
+    'email': email,
+    'deviceSecret': deviceSecret,
+    'expiresAt': expiresAt.toIso8601String(),
+    'resendAvailableAt': resendAvailableAt.toIso8601String(),
+    'codeLength': codeLength,
+  };
+
+  static PendingGuardianRequest? fromJson(Map<String, dynamic> json) {
+    try {
+      return PendingGuardianRequest(
+        requestId: json['requestId'] as String,
+        email: json['email'] as String,
+        deviceSecret: json['deviceSecret'] as String,
+        expiresAt: DateTime.parse(json['expiresAt'] as String),
+        resendAvailableAt: DateTime.parse(json['resendAvailableAt'] as String),
+        codeLength: json['codeLength'] as int? ?? defaultCodeLength,
+      );
+    } on Object {
+      return null;
+    }
+  }
+}
+
+class PendingGuardianRequestStore {
+  static const _key = 'guardian_login_pending_request';
+  static const FlutterSecureStorage _storage = FlutterSecureStorage(
+    iOptions: IOSOptions(accessibility: KeychainAccessibility.first_unlock),
+  );
+
+  const PendingGuardianRequestStore();
+
+  Future<PendingGuardianRequest?> read() async {
+    try {
+      final raw = await _storage.read(key: _key);
+      if (raw == null) return null;
+      return PendingGuardianRequest.fromJson(
+        jsonDecode(raw) as Map<String, dynamic>,
+      );
+    } on Object {
+      return null;
+    }
+  }
+
+  Future<void> write(PendingGuardianRequest request) =>
+      _storage.write(key: _key, value: jsonEncode(request.toJson()));
+
+  Future<void> clear() async {
+    try {
+      await _storage.delete(key: _key);
+    } on Object {
+      // Nothing stored or keystore unavailable.
+    }
+  }
+}

lib/background/widget_background_task.dart

@@ -6,6 +6,7 @@ import 'package:flutter/widgets.dart';
 import 'package:workmanager/workmanager.dart';
 
 import '../api/marianumconnect/marianumconnect_endpoint.dart';
+import '../api/marianumconnect/queries/timetable_custom_events/timetable_custom_events_get.dart';
 import '../api/marianumconnect/queries/timetable_get_holidays/timetable_get_holidays.dart';
 import '../api/marianumconnect/queries/timetable_get_holidays/timetable_get_holidays_response.dart';
 import '../api/marianumconnect/queries/timetable_get_rooms/timetable_get_rooms.dart';
@@ -14,11 +15,11 @@ import '../api/marianumconnect/queries/timetable_get_subjects/timetable_get_subj
 import '../api/marianumconnect/queries/timetable_get_subjects/timetable_get_subjects_response.dart';
 import '../api/marianumconnect/queries/timetable_get_timegrid/timetable_get_timegrid.dart';
 import '../api/marianumconnect/queries/timetable_get_timegrid/timetable_get_timegrid_response.dart';
-import '../api/marianumconnect/queries/timetable_get_week/timetable_get_week.dart';
-import '../api/mhsl/custom_timetable_event/get/get_custom_timetable_event.dart';
-import '../api/mhsl/custom_timetable_event/get/get_custom_timetable_event_params.dart';
 import '../api/mhsl/custom_timetable_event/get/get_custom_timetable_event_response.dart';
-import '../model/account_data.dart';
+import '../session/session.dart';
+import '../session/session_manager.dart';
+import '../state/app/modules/timetable/data_provider/timetable_data_provider.dart';
+import '../state/app/modules/timetable/subject/timetable_subject.dart';
 import '../widget_data/widget_data_mapper.dart';
 import '../widget_data/widget_publisher.dart';
 import '../widget_data/widget_sync.dart';
@@ -81,17 +82,17 @@ class WidgetBackgroundTask {
   /// Throws on fetch failure so the worker path can signal a retry.
   static Future<void> runRefreshNow({bool force = false}) async {
     await WidgetSync.ensureInitialized();
-    bool populated;
+    Session? session;
     try {
       // Bounded: a hanging keystore read must not stall the caller's budget
       // (FCM handler ~25s on iOS) forever.
-      populated = await AccountData().waitForPopulation().timeout(
+      session = await SessionManager().waitForLoad().timeout(
         const Duration(seconds: 10),
       );
     } on TimeoutException {
-      populated = false;
+      session = null;
     }
-    if (!populated) {
+    if (session == null) {
       // Deliberately does NOT flip the widget to logged-out: a failed or slow
       // keychain read (locked iOS device during the 06:00 silent push) is
       // indistinguishable from "never logged in" here, and blanking the
@@ -101,11 +102,23 @@ class WidgetBackgroundTask {
       return;
     }
     final fetchedAt = await WidgetSync.getFetchedAt();
-    if (shouldSkipRefresh(fetchedAt: fetchedAt, now: DateTime.now(), force: force)) {
+    if (shouldSkipRefresh(
+      fetchedAt: fetchedAt,
+      now: DateTime.now(),
+      force: force,
+    )) {
       log('[widget-refresh] snapshot is fresh, skipping refresh');
       return;
     }
-    await _refresh();
+    final subject = widgetRefreshSubject(
+      session: session,
+      stored: await WidgetSync.getSubject(),
+    );
+    if (subject == null) {
+      log('[widget-refresh] no plan selected yet, skipping refresh');
+      return;
+    }
+    await _refresh(subject);
   }
 
   static Future<void> cancelAll() async {
@@ -126,6 +139,16 @@ bool shouldSkipRefresh({
   return !age.isNegative && age < WidgetBackgroundTask.refreshDebounce;
 }
 
+/// The plan the background refresh loads. Guardians only get one once the app
+/// has published a child; before that there is nothing sensible to fetch.
+TimetableSubject? widgetRefreshSubject({
+  required Session session,
+  required TimetableSubject? stored,
+}) => switch (session) {
+  CredentialSession() => const OwnTimetable(),
+  GuardianSession() => stored is ChildTimetable ? stored : null,
+};
+
 @pragma('vm:entry-point')
 void _callbackDispatcher() {
   Workmanager().executeTask((task, inputData) async {
@@ -142,7 +165,7 @@ void _callbackDispatcher() {
   });
 }
 
-Future<void> _refresh() async {
+Future<void> _refresh(TimetableSubject subject) async {
   await WidgetSync.ensureInitialized();
   // The background isolate doesn't go through main.dart's BlocBuilder, so we
   // re-apply the endpoint the foreground last persisted. Without this the
@@ -165,9 +188,11 @@ Future<void> _refresh() async {
   // latency is the slowest request, not the sum (matters for the push path's
   // hard time budget). Reference-data failures fall through to null in the
   // mapper rather than aborting the whole refresh.
-  final timetableFuture = TimetableGetWeek().run(
+  final until = weekEndExclusive.subtract(const Duration(days: 1));
+  final timetableFuture = TimetableDataProvider.fetchWeek(
+    subject,
     from: weekStart,
-    until: weekEndExclusive.subtract(const Duration(days: 1)),
+    until: until,
   );
   final subjectsFuture = _runOrNull<TimetableGetSubjectsResponse>(
     () => TimetableGetSubjects().run(),
@@ -181,11 +206,11 @@ Future<void> _refresh() async {
   final timegridFuture = _runOrNull<TimetableGetTimegridResponse>(
     () => TimetableGetTimegrid().run(),
   );
-  final customEventsFuture = _runOrNull<GetCustomTimetableEventResponse>(
-    () => GetCustomTimetableEvent(
-      GetCustomTimetableEventParams(AccountData().getUserSecret()),
-    ).run(),
-  );
+  final customEventsFuture = subject.supportsCustomEvents
+      ? _runOrNull<GetCustomTimetableEventResponse>(
+          () => TimetableCustomEventsGet().run(),
+        )
+      : Future<GetCustomTimetableEventResponse?>.value();
   final timetable = await timetableFuture;
   final subjects = await subjectsFuture;
   final rooms = await roomsFuture;
@@ -195,9 +220,9 @@ Future<void> _refresh() async {
 
   final lessons = timetable.entries;
 
-  final [connectDouble, isTeacher] = await Future.wait([
+  final [connectDouble, showClassInsteadOfTeacher] = await Future.wait([
     WidgetSync.getConnectDoubleLessons(),
-    WidgetSync.getIsTeacher(),
+    WidgetSync.getShowClassInsteadOfTeacher(),
   ]);
   final dayData = WidgetDataMapper.buildDayData(
     now: now,
@@ -208,7 +233,7 @@ Future<void> _refresh() async {
     timegrid: timegrid,
     customEvents: customEvents,
     connectDoubleLessons: connectDouble,
-    showClassInsteadOfTeacher: isTeacher,
+    showClassInsteadOfTeacher: showClassInsteadOfTeacher,
   );
   final weekData = WidgetDataMapper.buildWeekData(
     now: now,
@@ -219,9 +244,15 @@ Future<void> _refresh() async {
     timegrid: timegrid,
     customEvents: customEvents,
     connectDoubleLessons: connectDouble,
-    showClassInsteadOfTeacher: isTeacher,
+    showClassInsteadOfTeacher: showClassInsteadOfTeacher,
   );
 
+  // The user may have switched the child while the requests ran; writing now
+  // would show the previous child's plan.
+  if (await WidgetSync.getSubject() != subject) {
+    log('[widget-bg] subject changed during refresh, discarding');
+    return;
+  }
   await WidgetSync.writeDayData(dayData);
   await WidgetSync.writeWeekData(weekData);
   await WidgetSync.setLoggedIn(true);

lib/main.dart

@@ -24,15 +24,17 @@ import 'api/marianumconnect/queries/get_breakers/get_breakers_response.dart';
 import 'api/marianumconnect/queries/report_client_error/client_error_reporter.dart';
 import 'api/marianumconnect/queries/telemetry_heartbeat/telemetry_heartbeat.dart';
 import 'app.dart';
+import 'auth_link/guardian_link_listener.dart';
 import 'background/widget_background_task.dart';
 import 'firebase_options.dart';
-import 'model/account_data.dart';
 import 'notification/notification_service.dart';
+import 'push/notification_permission_prompt.dart';
 import 'push/push_message_handler.dart';
 import 'push/push_registration.dart';
 import 'push/push_registration_store.dart';
 import 'push/push_renderer.dart';
 import 'routing/app_routes.dart';
+import 'session/session_manager.dart';
 import 'share_intent/share_intent_listener.dart';
 import 'state/app/modules/account/bloc/account_bloc.dart';
 import 'state/app/modules/account/bloc/account_state.dart';
@@ -40,14 +42,17 @@ import 'state/app/modules/breaker/bloc/breaker_bloc.dart';
 import 'state/app/modules/capabilities/bloc/capabilities_cubit.dart';
 import 'state/app/modules/chat/bloc/chat_bloc.dart';
 import 'state/app/modules/chat_list/bloc/chat_list_bloc.dart';
+import 'state/app/modules/children/child_selection_cubit.dart';
 import 'state/app/modules/nextcloud_capabilities/bloc/nextcloud_capabilities_cubit.dart';
+import 'state/app/modules/parent_letters/bloc/parent_letters_bloc.dart';
 import 'state/app/modules/settings/bloc/settings_cubit.dart';
-import 'state/app/modules/timetable/bloc/timetable_bloc.dart';
+import 'state/app/modules/timetable/primary/primary_timetable_scope.dart';
 import 'storage/hydrated_storage_bootstrap.dart';
 import 'storage/settings.dart';
 import 'theming/dark_app_theme.dart';
 import 'theming/light_app_theme.dart';
 import 'utils/app_paths.dart';
+import 'utils/debouncer.dart';
 import 'utils/downloads/download_manager.dart';
 import 'view/login/account_loading_screen.dart';
 import 'view/login/login.dart';
@@ -149,17 +154,18 @@ Future<void> main() async {
     _startupStep('documents dir', () async {
       AppPaths.documentsDir = (await getApplicationDocumentsDirectory()).path;
     }),
-    // The keychain may still be locked right after device unlock; AccountData
+    // The keychain may still be locked right after device unlock; the session
     // keeps retrying, so on timeout the app starts on the loading screen and
     // flips to the real state once the session is readable (see _MainState).
     _startupStep(
       'account data',
-      AccountData().waitForPopulation,
+      SessionManager().waitForLoad,
       timeout: const Duration(seconds: 5),
       // Expected on every background wake of a locked device; not an error.
       report: false,
     ),
     _startupStep('share intent', ShareIntentListener.instance.initialize),
+    _startupStep('guardian link', GuardianLinkListener.instance.initialize),
   ];
 
   log('starting app initialisation...');
@@ -215,7 +221,7 @@ Future<void> main() async {
   // has data ready by the time the user navigates to it. No-op when a
   // cached payload is already present, so this does not undo the day-long
   // root cache TTL.
-  if (AccountData().isPopulated()) {
+  if (SessionManager().hasNextcloud) {
     unawaited(
       ListFilesCache.prefetchRootListing().onError(
         (e, _) => log('Files root prefetch failed: $e'),
@@ -228,11 +234,17 @@ Future<void> main() async {
   // placeholder flash.
   AvatarDiskCache.instance.warmUp();
 
+  // Created eagerly so the endpoint is configured before anything below can
+  // issue a request (the primary timetable bloc loads on creation).
+  final settingsCubit = SettingsCubit();
+  _syncMarianumConnectEndpoint(settingsCubit.state);
+  settingsCubit.stream.listen(_syncMarianumConnectEndpoint);
+
   log('running app...');
   runApp(
     MultiBlocProvider(
       providers: [
-        BlocProvider<SettingsCubit>(create: (_) => SettingsCubit()),
+        BlocProvider<SettingsCubit>.value(value: settingsCubit),
         BlocProvider<AccountBloc>(
           create: (_) => AccountBloc(initialStatus: _initialAccountStatus()),
         ),
@@ -245,17 +257,32 @@ Future<void> main() async {
         BlocProvider<ChatBloc>(
           create: (ctx) => ChatBloc(chatListBloc: ctx.read<ChatListBloc>()),
         ),
-        BlocProvider<TimetableBloc>(create: (_) => TimetableBloc()),
+        BlocProvider<ChildSelectionCubit>(create: (_) => ChildSelectionCubit()),
+        BlocProvider<ParentLettersBloc>(create: (_) => ParentLettersBloc()),
       ],
-      child: const Main(),
+      child: const PrimaryTimetableScope(child: Main()),
     ),
   );
 }
 
+String? _syncedMcBaseUrl;
+
+/// Keeps the MC dio singleton aligned with the selected endpoint (live /
+/// beta / custom), mirrored into WidgetSync so the background isolate
+/// refreshes against the same endpoint. Settings emit on every toggle; only
+/// an actual URL change is applied.
+void _syncMarianumConnectEndpoint(Settings settings) {
+  final url = settings.devToolsSettings.resolveMarianumConnectBaseUrl();
+  if (url == _syncedMcBaseUrl) return;
+  _syncedMcBaseUrl = url;
+  MarianumConnectEndpoint.update(url);
+  unawaited(WidgetSync.setMarianumConnectBaseUrl(url));
+}
+
 AccountStatus _initialAccountStatus() {
-  final account = AccountData();
-  if (account.isPopulated()) return AccountStatus.loggedIn;
-  return account.isLoaded ? AccountStatus.loggedOut : AccountStatus.undefined;
+  final session = SessionManager();
+  if (session.isSignedIn) return AccountStatus.loggedIn;
+  return session.isLoaded ? AccountStatus.loggedOut : AccountStatus.undefined;
 }
 
 class Main extends StatefulWidget {
@@ -278,36 +305,56 @@ class _MainState extends State<Main> {
     super.initState();
     Jiffy.setLocale('de');
 
-    AccountData().waitForPopulation().then((value) {
+    SessionManager().unauthorizedSignal.addListener(_onUnauthorized);
+    SessionManager().waitForLoad().then((session) {
       if (!mounted) return;
       final accountBloc = context.read<AccountBloc>();
       accountBloc.setStatus(
-        value ? AccountStatus.loggedIn : AccountStatus.loggedOut,
+        session != null ? AccountStatus.loggedIn : AccountStatus.loggedOut,
       );
-      if (value) {
+      if (session != null) {
         _scheduleSessionValidation(accountBloc);
         // Cold start while already logged in: the account status doesn't
-        // change, so the loggedIn listener below never fires — refresh
-        // capabilities here, then self-heal the push registration.
-        final settingsCubit = context.read<SettingsCubit>();
-        unawaited(
-          context.read<CapabilitiesCubit>().load().then((_) {
-            if (!mounted) return;
-            _syncPush(settingsCubit, context.read<CapabilitiesCubit>());
-          }),
-        );
-        unawaited(context.read<NextcloudCapabilitiesCubit>().load());
+        // change, so the loggedIn listener below never fires.
+        _onSessionActive();
       }
     });
   }
 
-  /// Warms the core caches (timetable, chat list, files root) in the
-  /// background so the first screen render hits populated data.
+  /// Pulls the capability flags of the active account, then registers push
+  /// right away instead of deferring it to the next app start.
+  void _onSessionActive() {
+    final settingsCubit = context.read<SettingsCubit>();
+    final capabilitiesCubit = context.read<CapabilitiesCubit>();
+    unawaited(
+      capabilitiesCubit.load().then((_) {
+        if (!mounted) return;
+        _syncPush(settingsCubit, capabilitiesCubit);
+        _promptGuardianNotifications();
+      }),
+    );
+    unawaited(context.read<NextcloudCapabilitiesCubit>().load());
+  }
+
+  /// Waits for the post-login splash so the dialog never covers it; the
+  /// splash's completion calls this again.
+  void _promptGuardianNotifications() {
+    if (_showPostLoginSplash) return;
+    final overlayContext = AppRoutes.overlayContext;
+    if (overlayContext == null) return;
+    unawaited(maybePromptGuardianLoginNotifications(overlayContext));
+  }
+
+  /// Warms the chat list and files root in the background so the first screen
+  /// render hits populated data. The timetable needs no warm-up:
+  /// PrimaryTimetableScope creates a freshly loading bloc per account.
   void _prefetchBaseData(BuildContext context) {
-    context.read<TimetableBloc>().refresh();
     unawaited(context.read<ChatListBloc>().refresh(silent: true));
+    unawaited(context.read<ParentLettersBloc>().refresh(silent: true));
+    if (SessionManager().hasNextcloud) {
       unawaited(ListFilesCache.prefetchRootListing());
     }
+  }
 
   /// Registers/self-heals the push subscription whenever the backend advertises
   /// the capability — independent of the notification toggle, so a user with
@@ -329,6 +376,23 @@ class _MainState extends State<Main> {
     );
   }
 
+  @override
+  void dispose() {
+    SessionManager().unauthorizedSignal.removeListener(_onUnauthorized);
+    super.dispose();
+  }
+
+  void _onUnauthorized() {
+    if (!mounted) return;
+    final accountBloc = context.read<AccountBloc>();
+    if (accountBloc.state.status != AccountStatus.loggedIn) return;
+    Debouncer.throttle(
+      'sessionUnauthorized',
+      const Duration(seconds: 30),
+      () => _scheduleSessionValidation(accountBloc),
+    );
+  }
+
   /// Background credential check: a 401 means the password was rotated
   /// server-side, so the validator wipes the local session and flips the
   /// account bloc to `loggedOut` (sending the user to the login screen).
@@ -349,14 +413,6 @@ class _MainState extends State<Main> {
     child: BlocBuilder<SettingsCubit, Settings>(
       builder: (context, settings) {
         final devToolsSettings = settings.devToolsSettings;
-        // Keep the MC dio singleton aligned with the currently selected
-        // endpoint (live / beta / custom). Idempotent when the URL is
-        // unchanged so it's safe to call on every rebuild. Mirrored into
-        // WidgetSync so the background isolate refreshes against the same
-        // endpoint.
-        final mcBaseUrl = devToolsSettings.resolveMarianumConnectBaseUrl();
-        MarianumConnectEndpoint.update(mcBaseUrl);
-        unawaited(WidgetSync.setMarianumConnectBaseUrl(mcBaseUrl));
         // Mirror the notification toggle into group-scoped storage so the FCM
         // background isolate and the iOS NSE can suppress rendering when off.
         unawaited(
@@ -409,22 +465,8 @@ class _MainState extends State<Main> {
                   listenWhen: (previous, current) =>
                       previous.status != current.status,
                   listener: (context, accountState) {
-                    // Fresh login (loggedOut -> loggedIn): pull capability flags
-                    // for the newly authenticated user, then register push right
-                    // away instead of deferring it to the next app start.
                     if (accountState.status == AccountStatus.loggedIn) {
-                      final settingsCubit = context.read<SettingsCubit>();
-                      final capabilitiesCubit = context
-                          .read<CapabilitiesCubit>();
-                      unawaited(
-                        capabilitiesCubit.load().then((_) {
-                          if (!mounted) return;
-                          _syncPush(settingsCubit, capabilitiesCubit);
-                        }),
-                      );
-                      unawaited(
-                        context.read<NextcloudCapabilitiesCubit>().load(),
-                      );
+                      _onSessionActive();
                       _showPostLoginSplash = true;
                       _appMounted = false;
                       WidgetsBinding.instance.addPostFrameCallback((_) {
@@ -449,11 +491,13 @@ class _MainState extends State<Main> {
                     // — by the time it runs the dialog/Settings context is
                     // gone but this listener context is still valid.
                     final settingsCubit = context.read<SettingsCubit>();
-                    final timetableBloc = context.read<TimetableBloc>();
-                    final chatListBloc = context.read<ChatListBloc>();
-                    final chatBloc = context.read<ChatBloc>();
                     final breakerBloc = context.read<BreakerBloc>();
                     final capabilitiesCubit = context.read<CapabilitiesCubit>();
+                    final childSelectionCubit = context
+                        .read<ChildSelectionCubit>();
+                    final chatListBloc = context.read<ChatListBloc>();
+                    final parentLettersBloc = context.read<ParentLettersBloc>();
+                    final chatBloc = context.read<ChatBloc>();
                     final nextcloudCapabilitiesCubit = context
                         .read<NextcloudCapabilitiesCubit>();
                     // Defer the actual wipe until after this frame so the
@@ -464,8 +508,9 @@ class _MainState extends State<Main> {
                       unawaited(
                         _wipeUserState(
                           settingsCubit: settingsCubit,
-                          timetableBloc: timetableBloc,
+                          childSelectionCubit: childSelectionCubit,
                           chatListBloc: chatListBloc,
+                          parentLettersBloc: parentLettersBloc,
                           chatBloc: chatBloc,
                           breakerBloc: breakerBloc,
                           capabilitiesCubit: capabilitiesCubit,
@@ -486,9 +531,10 @@ class _MainState extends State<Main> {
                             if (_showPostLoginSplash)
                               PostLoginSplash(
                                 key: const ValueKey('post-login-splash'),
-                                onComplete: () => setState(
-                                  () => _showPostLoginSplash = false,
-                                ),
+                                onComplete: () {
+                                  setState(() => _showPostLoginSplash = false);
+                                  _promptGuardianNotifications();
+                                },
                               ),
                           ],
                         );
@@ -510,8 +556,9 @@ class _MainState extends State<Main> {
 
 Future<void> _wipeUserState({
   required SettingsCubit settingsCubit,
-  required TimetableBloc timetableBloc,
+  required ChildSelectionCubit childSelectionCubit,
   required ChatListBloc chatListBloc,
+  required ParentLettersBloc parentLettersBloc,
   required ChatBloc chatBloc,
   required BreakerBloc breakerBloc,
   required CapabilitiesCubit capabilitiesCubit,
@@ -523,13 +570,17 @@ Future<void> _wipeUserState({
     // wraps MaterialApp, so emit'ing a fresh state would tear down the
     // freshly-mounted Login tree and leave the user with a blank screen
     // (the MaterialApp.builder backdrop) until the next interaction.
+    // The timetable bloc is not reset here: PrimaryTimetableScope replaces it
+    // on the status change, and HydratedBloc.storage.clear() below drops the
+    // cached plans of every subject.
+    childSelectionCubit.reset();
+    capabilitiesCubit.reset();
+    nextcloudCapabilitiesCubit.reset();
     await Future.wait([
-      timetableBloc.reset(),
       chatListBloc.reset(),
+      parentLettersBloc.reset(),
       chatBloc.reset(),
       breakerBloc.reset(),
-      capabilitiesCubit.reset(),
-      nextcloudCapabilitiesCubit.reset(),
     ]);
     final prefs = await SharedPreferences.getInstance();
     await prefs.clear();

lib/model/account_data.dart

@@ -1,333 +0,0 @@
-import 'dart:async';
-import 'dart:convert';
-import 'dart:developer';
-import 'dart:io';
-
-import 'package:crypto/crypto.dart';
-import 'package:flutter_secure_storage/flutter_secure_storage.dart';
-import 'package:shared_preferences/shared_preferences.dart';
-
-import '../push/push_secure_storage.dart';
-import '../utils/exponential_backoff.dart';
-
-class AccountData {
-  static const _usernameField = 'username';
-  static const _passwordField = 'password';
-  // App passwords live in the push-shared (group-scoped) keystore so the iOS
-  // Notification Service Extension can authenticate Nextcloud calls too.
-  // The talk password authenticates the second (apptype=talk) push
-  // registration — Nextcloud binds each push subscription to its session
-  // token, so two registrations need two app passwords.
-  static const _appPasswordField = 'nextcloud_app_password';
-  static const _appPasswordTalkField = 'nextcloud_app_password_talk';
-  // Marks accounts whose Nextcloud credentials came from Login Flow v2 (2FA):
-  // the real password is not valid against Nextcloud, only the flow-issued
-  // app password is — and no further app passwords can be minted silently.
-  static const _loginFlowField = 'nextcloud_login_flow';
-  // Persists the demo session across cold starts (see DemoMode).
-  static const _demoField = 'is_demo';
-  // Keeps isPopulated()/getPassword() valid; demo mode never uses a real one.
-  static const _demoPasswordPlaceholder = 'demo';
-
-  // `first_unlock` so a background launch on a locked device (silent push,
-  // BGAppRefresh) can still read the session. Items written by older versions
-  // carry the plugin default `unlocked` and are invisible to this instance
-  // until _migrateKeychainAccessibility moved them over.
-  static const FlutterSecureStorage _secureStorage = FlutterSecureStorage(
-    iOptions: IOSOptions(accessibility: KeychainAccessibility.first_unlock),
-  );
-  static const FlutterSecureStorage _legacySecureStorage = FlutterSecureStorage(
-    iOptions: IOSOptions(accessibility: KeychainAccessibility.unlocked),
-  );
-  static const List<String> _sessionFields = [
-    _usernameField,
-    _passwordField,
-    _demoField,
-    _loginFlowField,
-  ];
-
-  static final AccountData _instance = AccountData._construct();
-  Completer<void> _populated = Completer();
-
-  factory AccountData() => _instance;
-
-  AccountData._construct() {
-    unawaited(_loadWithRetry());
-  }
-
-  String? _username;
-  String? _password;
-  String? _appPassword;
-  String? _appPasswordTalk;
-  bool _isDemo = false;
-  bool _usesLoginFlow = false;
-
-  /// True while the active session is a local demo session (see DemoMode).
-  bool get isDemo => _isDemo;
-
-  /// True when the Nextcloud credentials were obtained via Login Flow v2
-  /// (browser login, e.g. because the account has two-factor authentication).
-  /// In that mode the stored real password only authenticates MarianumConnect;
-  /// every Nextcloud call must use the flow-issued app password.
-  bool get usesLoginFlow => _usesLoginFlow;
-
-  String getUsername() {
-    if (_username == null) throw Exception('Username not initialized');
-    return _username!;
-  }
-
-  String getPassword() {
-    if (_password == null) throw Exception('Password not initialized');
-    return _password!;
-  }
-
-  String getUserSecret() => sha512
-      .convert(utf8.encode('${getUsername()}:${getPassword()}'))
-      .toString();
-
-  Future<void> setData(String username, String password) async {
-    await _secureStorage.write(key: _usernameField, value: username);
-    await _secureStorage.write(key: _passwordField, value: password);
-    _username = username;
-    _password = password;
-    if (!_populated.isCompleted) _populated.complete();
-  }
-
-  /// Enters a local demo session for [username] — no real credentials or token;
-  /// every backend is served from fixtures while [isDemo] is true (see DemoMode).
-  Future<void> setDemo(String username) async {
-    await _secureStorage.write(key: _usernameField, value: username);
-    await _secureStorage.write(
-      key: _passwordField,
-      value: _demoPasswordPlaceholder,
-    );
-    await _secureStorage.write(key: _demoField, value: 'true');
-    _username = username;
-    _password = _demoPasswordPlaceholder;
-    _isDemo = true;
-    if (!_populated.isCompleted) _populated.complete();
-  }
-
-  Future<void> removeData() async {
-    _populated = Completer();
-    _username = null;
-    _password = null;
-    _appPassword = null;
-    _appPasswordTalk = null;
-    _isDemo = false;
-    _usesLoginFlow = false;
-    await _secureStorage.delete(key: _usernameField);
-    await _secureStorage.delete(key: _passwordField);
-    await _secureStorage.delete(key: _demoField);
-    await _secureStorage.delete(key: _loginFlowField);
-    await _clearAppPasswordStorage();
-    await _clearAppPasswordTalkStorage();
-  }
-
-  /// Persists a freshly minted Nextcloud app password. After this every
-  /// [getBasicAuthHeader] call authenticates with the app password instead of
-  /// the real password.
-  Future<void> setAppPassword(String appPassword) async {
-    _appPassword = appPassword;
-    try {
-      await pushSecureStorage.write(key: _appPasswordField, value: appPassword);
-    } on Object {
-      // Group-scoped keystore may be unavailable (e.g. iOS entitlement not yet
-      // provisioned). Keeping it in memory still lets this session use it.
-    }
-  }
-
-  Future<void> clearAppPassword() async {
-    _appPassword = null;
-    await _clearAppPasswordStorage();
-  }
-
-  /// Adopts an app password obtained via Login Flow v2 and switches the
-  /// account into flow mode (see [usesLoginFlow]). Any previously stored Talk
-  /// app password belonged to the old session era and is dropped — the second
-  /// (optional) flow pass stores a fresh one via [setAppPasswordTalk].
-  Future<void> setLoginFlow(String appPassword) async {
-    await setAppPassword(appPassword);
-    await clearAppPasswordTalk();
-    _usesLoginFlow = true;
-    await _secureStorage.write(key: _loginFlowField, value: 'true');
-  }
-
-  bool hasAppPassword() => _appPassword != null && _appPassword!.isNotEmpty;
-
-  /// Persists the app password backing the Talk push registration.
-  Future<void> setAppPasswordTalk(String appPassword) async {
-    _appPasswordTalk = appPassword;
-    try {
-      await pushSecureStorage.write(
-        key: _appPasswordTalkField,
-        value: appPassword,
-      );
-    } on Object {
-      // Group-scoped keystore may be unavailable — in-memory still works for
-      // this session, matching setAppPassword.
-    }
-  }
-
-  Future<void> clearAppPasswordTalk() async {
-    _appPasswordTalk = null;
-    await _clearAppPasswordTalkStorage();
-  }
-
-  bool hasAppPasswordTalk() =>
-      _appPasswordTalk != null && _appPasswordTalk!.isNotEmpty;
-
-  Future<void> _clearAppPasswordStorage() async {
-    try {
-      await pushSecureStorage.delete(key: _appPasswordField);
-    } on Object {
-      // ignore — nothing stored or keystore unavailable
-    }
-  }
-
-  Future<void> _clearAppPasswordTalkStorage() async {
-    try {
-      await pushSecureStorage.delete(key: _appPasswordTalkField);
-    } on Object {
-      // ignore — nothing stored or keystore unavailable
-    }
-  }
-
-  /// iOS keychain reads fail while protected data is unavailable (app launch
-  /// racing the unlock, background wake on a locked device). Without a retry
-  /// the completer never resolved and the app stayed on the launch screen.
-  Future<void> _loadWithRetry() async {
-    for (var attempt = 1; !_populated.isCompleted; attempt++) {
-      try {
-        await _migrateAndLoad();
-        return;
-      } catch (e, s) {
-        log('AccountData load failed (attempt $attempt): $e', stackTrace: s);
-        await Future<void>.delayed(exponentialBackoff(attempt));
-      }
-    }
-  }
-
-  /// Stops waiting for the stored session; the app then behaves as logged
-  /// out. The keychain entries stay untouched so a later start can still
-  /// restore the session.
-  void abandonLoad() {
-    if (!_populated.isCompleted) _populated.complete();
-  }
-
-  Future<void> _migrateAndLoad() async {
-    await _migrateFromLegacyStorage();
-    await _migrateKeychainAccessibility();
-    _username = await _secureStorage.read(key: _usernameField);
-    _password = await _secureStorage.read(key: _passwordField);
-    _isDemo = (await _secureStorage.read(key: _demoField)) == 'true';
-    _usesLoginFlow =
-        (await _secureStorage.read(key: _loginFlowField)) == 'true';
-    try {
-      _appPassword = await pushSecureStorage.read(key: _appPasswordField);
-      _appPasswordTalk = await pushSecureStorage.read(
-        key: _appPasswordTalkField,
-      );
-    } on Object {
-      _appPassword = null;
-      _appPasswordTalk = null;
-    }
-    if (!_populated.isCompleted) _populated.complete();
-  }
-
-  // Move credentials from the old SharedPreferences plain-text storage into the
-  // platform's secure keystore. Run once per install and clear the legacy keys.
-  Future<void> _migrateFromLegacyStorage() async {
-    final prefs = await SharedPreferences.getInstance();
-    final legacyUsername = prefs.getString(_usernameField);
-    final legacyPassword = prefs.getString(_passwordField);
-    if (legacyUsername == null || legacyPassword == null) return;
-
-    final hasSecure = (await _secureStorage.read(key: _usernameField)) != null;
-    if (!hasSecure) {
-      await _secureStorage.write(key: _usernameField, value: legacyUsername);
-      await _secureStorage.write(key: _passwordField, value: legacyPassword);
-    }
-    await prefs.remove(_usernameField);
-    await prefs.remove(_passwordField);
-  }
-
-  Future<void> _migrateKeychainAccessibility() async {
-    if (!Platform.isIOS) return;
-    for (final field in _sessionFields) {
-      final value = await _legacySecureStorage.read(key: field);
-      if (value == null) continue;
-      // Same account+service: the legacy item has to go before the re-add.
-      await _legacySecureStorage.delete(key: field);
-      await _secureStorage.write(key: field, value: value);
-    }
-  }
-
-  Future<bool> waitForPopulation() async {
-    await _populated.future;
-    return isPopulated();
-  }
-
-  /// True once the stored session has been read (or given up on).
-  bool get isLoaded => _populated.isCompleted;
-
-  bool isPopulated() => _username != null && _password != null;
-
-  /// Returns the value for an HTTP `Authorization` header using HTTP Basic.
-  /// Prefer this over embedding credentials in URLs — error logs and crash
-  /// reports often capture the URL but not headers.
-  String getBasicAuthHeader() {
-    _requirePopulated();
-    // Prefer the scoped app password once available; it survives real-password
-    // rotation and is what the push-v2 registration is bound to.
-    return _basicAuth(_appPassword ?? _password!);
-  }
-
-  /// Basic-auth header using the Talk app password — authenticates the
-  /// apptype=talk push registration (and its unregister). Throws when the
-  /// talk password has not been minted yet; callers treat that as a failed
-  /// talk registration and retry on the next start.
-  String getTalkBasicAuthHeader() {
-    _requirePopulated();
-    if (!hasAppPasswordTalk()) {
-      // Login-flow account whose second (talk) flow pass was skipped: no
-      // silent minting possible, the talk registration shares the single
-      // flow-issued credential.
-      if (_usesLoginFlow && hasAppPassword()) return _basicAuth(_appPassword!);
-      throw StateError('Talk app password not available yet');
-    }
-    return _basicAuth(_appPasswordTalk!);
-  }
-
-  /// Basic-auth header that always uses the real password. Needed exactly once,
-  /// to mint the app password via `core/getapppassword` (an app password cannot
-  /// mint another).
-  String getRealPasswordBasicAuthHeader() {
-    _requirePopulated();
-    return _basicAuth(_password!);
-  }
-
-  /// Secret authenticating against Nextcloud: the app password once available
-  /// (minted or flow-issued), otherwise the real password. Mirrors the
-  /// preference of [getBasicAuthHeader] for clients that need the raw secret
-  /// (WebDAV client construction).
-  String getNextcloudSecret() {
-    _requirePopulated();
-    return _appPassword ?? _password!;
-  }
-
-  void _requirePopulated() {
-    if (!isPopulated()) {
-      throw Exception(
-        'AccountData (e.g. username or password) is not initialized!',
-      );
-    }
-  }
-
-  String _basicAuth(String secret) =>
-      'Basic ${base64Encode(utf8.encode('$_username:$secret'))}';
-
-  /// Convenience wrapper around [getBasicAuthHeader] returning a single-entry
-  /// header map ready to merge into HTTP request headers.
-  Map<String, String> authHeaders() => {'Authorization': getBasicAuthHeader()};
-}

lib/notification/notification_controller.dart

@@ -5,7 +5,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 
 import '../push/push_message_handler.dart';
-import '../routing/app_routes.dart';
+import '../push/push_target.dart';
 import '../state/app/modules/chat/bloc/chat_bloc.dart';
 import '../widget/debug/debug_tile.dart';
 import '../widget/debug/json_viewer.dart';
@@ -42,18 +42,15 @@ class NotificationController {
     RemoteMessage message,
     BuildContext context,
   ) async {
-    final newsletterId = _extractNewsletterId(message);
-    if (newsletterId != null) {
-      AppRoutes.openNewsletterById(
+    final target = resolvePushTarget(message.data);
+    if (target != null) {
+      NotificationTasks.openPushTarget(
         context,
-        id: newsletterId,
+        target,
         title: message.notification?.title,
       );
     } else {
-      NotificationTasks.navigateToTalk(
-        context,
-        chatToken: _extractChatToken(message),
-      );
+      NotificationTasks.navigateToTalk(context);
     }
     NotificationTasks.updateProviders(context);
     unawaited(NotificationTasks.refreshBadge());
@@ -68,17 +65,4 @@ class NotificationController {
       );
     });
   }
-
-  static String? _extractChatToken(RemoteMessage message) {
-    for (final key in const ['chatToken', 'token', 'roomToken']) {
-      final value = message.data[key];
-      if (value is String && value.isNotEmpty) return value;
-    }
-    return null;
-  }
-
-  static String? _extractNewsletterId(RemoteMessage message) {
-    final value = message.data['newsletterId'];
-    return value is String && value.isNotEmpty ? value : null;
-  }
 }

lib/notification/notification_tasks.dart

@@ -7,8 +7,13 @@ import 'package:flutter_app_badge/flutter_app_badge.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 
 import '../push/chat_thread_store.dart';
+import '../push/push_renderer.dart';
+import '../push/push_target.dart';
 import '../routing/app_routes.dart';
+import '../session/session_manager.dart';
+import '../state/app/modules/app_modules.dart';
 import '../state/app/modules/chat_list/bloc/chat_list_bloc.dart';
+import '../state/app/modules/parent_letters/bloc/parent_letters_bloc.dart';
 import 'notification_service.dart';
 
 class NotificationTasks {
@@ -70,12 +75,50 @@ class NotificationTasks {
   /// even if the user has already left.
   static void updateProviders(BuildContext context) {
     context.read<ChatListBloc>().refresh();
+    context.read<ParentLettersBloc>().refresh(silent: true);
+  }
+
+  /// [title] is the notification title, when the tap came with one.
+  static void openPushTarget(
+    BuildContext context,
+    PushTarget target, {
+    String? title,
+  }) {
+    switch (target) {
+      case ParentLetterTarget(:final letterId):
+        if (AppModule.isAvailableFor(
+          Modules.parentLetters,
+          SessionManager().current,
+        )) {
+          AppRoutes.openParentLetter(context, id: letterId);
+        }
+      case NewsletterTarget(:final newsletterId):
+        AppRoutes.openNewsletterById(context, id: newsletterId, title: title);
+      case ChatTarget(:final chatToken):
+        navigateToTalk(context, chatToken: chatToken);
+    }
+  }
+
+  /// Removes the letter's tray notification (Android; iOS alerts are posted by
+  /// the system and cannot be addressed by id).
+  static Future<void> clearParentLetterNotification(String letterId) async {
+    try {
+      await NotificationService().flutterLocalNotificationsPlugin.cancel(
+        id: PushRenderer.parentLetterNotificationId(letterId),
+      );
+      await refreshBadge();
+    } on Object catch (e) {
+      log('Parent letter notification cleanup failed: $e');
+    }
   }
 
   /// Switches to the Talk tab. If [chatToken] is provided, also schedules
   /// the matching chat to be opened automatically once the chat list view
   /// resolves the token (handled inside [ChatList]).
   static void navigateToTalk(BuildContext context, {String? chatToken}) {
+    if (!AppModule.isAvailableFor(Modules.talk, SessionManager().current)) {
+      return;
+    }
     if (chatToken != null && chatToken.isNotEmpty) {
       AppRoutes.openChatByToken(context, chatToken);
     } else {

lib/push/direct_push_registration.dart

@@ -0,0 +1,71 @@
+import 'dart:developer';
+
+import 'package:firebase_messaging/firebase_messaging.dart';
+
+import '../api/marianumconnect/queries/push_device_register/push_device_register.dart';
+import '../api/marianumconnect/queries/push_device_unregister/push_device_unregister.dart';
+import '../utils/random_id.dart';
+import 'push_device_info.dart';
+import 'push_secure_storage.dart';
+
+/// Push registration for accounts without Nextcloud (guardians): the device
+/// registers straight with MarianumConnect and only receives its direct
+/// pushes (newsletter, widget refresh, later guardian messages). Nextcloud
+/// normally supplies the device identifier; here a random one is kept per
+/// install.
+class DirectPushRegistration {
+  static const String registrationType = 'direct';
+  static const _deviceIdentifierKey = 'push_direct_device_identifier';
+
+  final FlutterSecureStorageLike _storage;
+
+  const DirectPushRegistration({
+    FlutterSecureStorageLike storage = const PushSecureStorage(),
+  }) : _storage = storage;
+
+  Future<bool> register() async {
+    try {
+      final (fcmToken, appVersion, identifier) = await (
+        FirebaseMessaging.instance.getToken(),
+        pushAppVersion(),
+        deviceIdentifier(),
+      ).wait;
+      if (fcmToken == null || fcmToken.isEmpty) {
+        log('Push (direct): no FCM token, skipping registration');
+        return false;
+      }
+      await PushDeviceRegister().run(
+        deviceIdentifier: identifier,
+        pushToken: fcmToken,
+        platform: pushPlatform,
+        registrationType: registrationType,
+        appVersion: appVersion,
+      );
+      return true;
+    } on Object catch (e) {
+      log('Push (direct): registration failed: $e');
+      return false;
+    }
+  }
+
+  Future<void> unregister() async {
+    final identifier = await _storage.read(key: _deviceIdentifierKey);
+    if (identifier == null) return;
+    try {
+      await PushDeviceUnregister().run(deviceIdentifier: identifier);
+    } on Object catch (e) {
+      log('Push (direct): unregister failed: $e');
+    }
+    await _storage.delete(key: _deviceIdentifierKey);
+  }
+
+  /// Stable per install until [unregister], so re-registrations upsert the
+  /// same server row instead of piling up devices.
+  Future<String> deviceIdentifier() async {
+    final stored = await _storage.read(key: _deviceIdentifierKey);
+    if (stored != null && stored.isNotEmpty) return stored;
+    final fresh = randomHexId();
+    await _storage.write(key: _deviceIdentifierKey, value: fresh);
+    return fresh;
+  }
+}

lib/push/notification_permission_prompt.dart

@@ -0,0 +1,195 @@
+import 'dart:async';
+import 'dart:developer';
+
+import 'package:app_settings/app_settings.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+
+import '../session/session_manager.dart';
+import '../state/app/modules/app_modules.dart';
+import '../state/app/modules/capabilities/bloc/capabilities_cubit.dart';
+import '../state/app/modules/settings/bloc/settings_cubit.dart';
+import '../storage/notification_settings.dart';
+import '../widget/confirm_dialog.dart';
+import 'push_registration.dart';
+
+const _talkExplanation =
+    'Damit du keine neuen Nachrichten im Talk verpasst, fragen wir dich '
+    'gleich nach der Erlaubnis für Benachrichtigungen. Bitte akzeptiere '
+    'sie, um Push-Nachrichten zu erhalten.';
+const _talkDeclinedNote =
+    'Ohne die Berechtigung erhältst du keine Benachrichtigungen bei neuen '
+    'Talk-Nachrichten. Du kannst sie jederzeit in den Systemeinstellungen '
+    'deines Geräts nachträglich aktivieren.';
+const _parentLetterExplanation =
+    'Damit du keine Elternbriefe der Schule verpasst, fragen wir dich gleich '
+    'nach der Erlaubnis für Benachrichtigungen. Bitte akzeptiere sie, um '
+    'Push-Nachrichten zu erhalten.';
+const _parentLetterDeclinedNote =
+    'Ohne die Berechtigung erhältst du keine Benachrichtigungen bei neuen '
+    'Elternbriefen. Du kannst sie jederzeit in den Systemeinstellungen deines '
+    'Geräts nachträglich aktivieren.';
+
+/// The occasions with a guided notification-permission flow. Each runs at
+/// most once per install, guarded by its own flag in [NotificationSettings].
+enum _PermissionPrompt {
+  talkVisit(_talkExplanation, _talkDeclinedNote),
+  guardianLogin(
+    _parentLetterExplanation,
+    _parentLetterDeclinedNote,
+    module: Modules.parentLetters,
+    spentOnDisplay: true,
+  ),
+  parentLettersVisit(
+    _parentLetterExplanation,
+    _parentLetterDeclinedNote,
+    module: Modules.parentLetters,
+  );
+
+  const _PermissionPrompt(
+    this.explanation,
+    this.declinedNote, {
+    this.module,
+    this.spentOnDisplay = false,
+  });
+
+  final String explanation;
+  final String declinedNote;
+
+  /// Only sessions that have this module are asked.
+  final Modules? module;
+
+  /// Spends the one-shot as soon as the explanation is displayed, so a
+  /// dismissed dialog does not come back on every app start.
+  final bool spentOnDisplay;
+
+  bool wasShown(NotificationSettings settings) => switch (this) {
+    talkVisit => settings.talkPermissionPromptShown,
+    guardianLogin => settings.guardianLoginPromptShown,
+    parentLettersVisit => settings.parentLettersPromptShown,
+  };
+
+  void markShown(NotificationSettings settings) {
+    switch (this) {
+      case talkVisit:
+        settings.talkPermissionPromptShown = true;
+      case guardianLogin:
+        settings.guardianLoginPromptShown = true;
+      case parentLettersVisit:
+        settings.parentLettersPromptShown = true;
+    }
+  }
+}
+
+/// Shows the one-time notification-permission flow on the first Talk visit.
+///
+/// The OS prompt is deliberately kept out of the cold-start path (younger users
+/// decline it reflexively before ever seeing why they'd want it). Instead, the
+/// first time Talk is opened we explain the request, then trigger the OS prompt,
+/// and — if declined — offer a shortcut to the system settings.
+///
+/// Runs at most once per install (guarded by `talkPermissionPromptShown`).
+Future<void> maybePromptTalkNotifications(BuildContext context) =>
+    _maybePrompt(context, _PermissionPrompt.talkVisit);
+
+/// Accounts that receive parent letters never reach the Talk flow, so they
+/// are asked once right after signing in.
+Future<void> maybePromptGuardianLoginNotifications(BuildContext context) =>
+    _maybePrompt(context, _PermissionPrompt.guardianLogin);
+
+/// Second chance with context: explains the request once more on the first
+/// visit of the parent letters when the permission is still missing.
+Future<void> maybePromptParentLetterNotifications(BuildContext context) =>
+    _maybePrompt(context, _PermissionPrompt.parentLettersVisit);
+
+bool _promptInFlight = false;
+
+Future<void> _maybePrompt(
+  BuildContext context,
+  _PermissionPrompt prompt,
+) async {
+  final module = prompt.module;
+  if (module != null &&
+      !AppModule.isAvailableFor(module, SessionManager().current)) {
+    return;
+  }
+
+  final settings = context.read<SettingsCubit>();
+  final notificationSettings = settings.val().notificationSettings;
+
+  // Already handled once, or the user opted out of push entirely.
+  if (prompt.wasShown(notificationSettings)) return;
+  if (!notificationSettings.enabled) return;
+
+  // Capabilities may still be loading on a fresh cold start; retry on the next
+  // occasion instead of burning the one-shot flag.
+  if (!context.read<CapabilitiesCubit>().canReceivePushNotifications) return;
+
+  if (_promptInFlight) return;
+  _promptInFlight = true;
+  try {
+    // Users who already granted the permission: register silently and mark the
+    // prompt as handled without showing any dialog.
+    if (await PushRegistration.isOsPermissionGranted()) {
+      prompt.markShown(settings.val(write: true).notificationSettings);
+      unawaited(PushRegistration().register());
+      return;
+    }
+
+    if (!context.mounted) return;
+
+    if (prompt.spentOnDisplay) {
+      prompt.markShown(settings.val(write: true).notificationSettings);
+    }
+    // The OS prompt (and its "declined" follow-up) outlive this dialog, so
+    // hold on to them: releasing the guard at the dialog's close would let a
+    // second occasion stack another dialog over the pending OS prompt.
+    Future<void>? permissionRequest;
+    await showDialog<void>(
+      context: context,
+      builder: ConfirmDialog(
+        icon: Icons.notifications_active_outlined,
+        title: 'Benachrichtigungen aktivieren',
+        content: prompt.explanation,
+        confirmButton: 'Weiter',
+        cancelButton: null,
+        onConfirm: () =>
+            permissionRequest = _requestPermission(context, settings, prompt),
+      ).build,
+    );
+    await permissionRequest;
+  } finally {
+    _promptInFlight = false;
+  }
+}
+
+Future<void> _requestPermission(
+  BuildContext context,
+  SettingsCubit settings,
+  _PermissionPrompt prompt,
+) async {
+  final granted = await PushRegistration.requestOsPermission();
+
+  // Mark handled regardless of the outcome — the user can re-enable later via
+  // the system settings; we don't want to prompt again on the next occasion.
+  prompt.markShown(settings.val(write: true).notificationSettings);
+
+  if (granted) {
+    unawaited(PushRegistration().register());
+    return;
+  }
+
+  log('Push: notification permission declined on ${prompt.name}');
+
+  if (!context.mounted) return;
+
+  ConfirmDialog(
+    icon: Icons.notifications_off_outlined,
+    title: 'Benachrichtigungen deaktiviert',
+    content: prompt.declinedNote,
+    confirmButton: 'Einstellungen öffnen',
+    cancelButton: 'Später',
+    onConfirm: () =>
+        AppSettings.openAppSettings(type: AppSettingsType.notification),
+  ).asDialog(context);
+}

lib/push/push_actions.dart

@@ -8,8 +8,8 @@ import 'package:flutter_local_notifications/flutter_local_notifications.dart';
 import 'package:http/http.dart' as http;
 
 import '../api/marianumcloud/nextcloud_ocs.dart';
-import '../model/account_data.dart';
 import '../notification/notification_service.dart';
+import '../session/session_manager.dart';
 import 'chat_thread_store.dart';
 import 'nid_store.dart';
 import 'push_renderer.dart';
@@ -38,7 +38,7 @@ void _plog(String message) {
 /// Handles Talk notification actions (inline reply, mark-as-read). Runs in the
 /// background isolate spawned by flutter_local_notifications, so it may not
 /// share any app state — it reads credentials straight from secure storage via
-/// the [AccountData] singleton after awaiting population.
+/// the [SessionManager] singleton after awaiting the stored session.
 ///
 /// The class-level `vm:entry-point` pragma is REQUIRED in addition to the one
 /// on [handleBackgroundResponse]: the callback is resolved via
@@ -56,7 +56,7 @@ class PushActions {
   ) async {
     // The FLN action isolate starts WITHOUT main(): unlike the FCM background
     // isolate, plugins are not registered automatically there. Without this,
-    // AccountData's secure-storage/prefs reads throw or never complete → no
+    // The session's secure-storage/prefs reads throw or never complete → no
     // auth header, the Talk POST never happens and the RemoteInput spinner
     // runs forever.
     DartPluginRegistrant.ensureInitialized();
@@ -125,7 +125,8 @@ class PushActions {
   /// any) followed by the technical reason.
   static String actionFailureBody({String? lostText, required String detail}) {
     return [
-      if (lostText != null && lostText.isNotEmpty) 'Deine Nachricht: „$lostText“',
+      if (lostText != null && lostText.isNotEmpty)
+        'Deine Nachricht: „$lostText“',
       'Grund: $detail',
     ].join('\n');
   }
@@ -188,7 +189,10 @@ class PushActions {
   static Future<({bool ok, String detail})> sendReply(
     String chatToken,
     String message,
-  ) => _ocsPost('apps/spreed/api/v1/chat/$chatToken', body: {'message': message});
+  ) => _ocsPost(
+    'apps/spreed/api/v1/chat/$chatToken',
+    body: {'message': message},
+  );
 
   static Future<({bool ok, String detail})> markRead(String chatToken) =>
       _ocsPost('apps/spreed/api/v1/chat/$chatToken/read');
@@ -200,10 +204,10 @@ class PushActions {
     try {
       // Bounded: a hanging population (e.g. keystore issue) must fail the
       // action instead of leaving the notification spinner running forever.
-      final populated = await AccountData().waitForPopulation().timeout(
+      final session = await SessionManager().waitForLoad().timeout(
         const Duration(seconds: 10),
       );
-      if (!populated) {
+      if (session?.nextcloud == null) {
         _plog('Push action $path aborted: credentials unreadable in isolate');
         return (
           ok: false,

lib/push/push_device_info.dart

@@ -0,0 +1,15 @@
+import 'dart:io';
+
+import 'package:package_info_plus/package_info_plus.dart';
+
+/// Platform value MarianumConnect expects in push registrations.
+String get pushPlatform => Platform.isIOS ? 'ios' : 'android';
+
+/// App version sent along with push registrations; null when unavailable.
+Future<String?> pushAppVersion() async {
+  try {
+    return (await PackageInfo.fromPlatform()).version;
+  } on Object {
+    return null;
+  }
+}

lib/push/push_registration.dart

@@ -3,7 +3,6 @@ import 'dart:io';
 
 import 'package:firebase_messaging/firebase_messaging.dart';
 import 'package:nextcloud/notifications.dart' show generatePushTokenHash;
-import 'package:package_info_plus/package_info_plus.dart';
 
 import '../api/demo/demo_mode.dart';
 import '../api/marianumcloud/app_password/delete_app_password.dart';
@@ -11,9 +10,12 @@ import '../api/marianumcloud/app_password/get_app_password.dart';
 import '../api/marianumconnect/marianumconnect_endpoint.dart';
 import '../api/marianumconnect/queries/push_device_register/push_device_register.dart';
 import '../api/marianumconnect/queries/push_device_unregister/push_device_unregister.dart';
-import '../model/account_data.dart';
 import '../model/endpoint_data.dart';
+import '../session/nextcloud_credentials.dart';
+import '../session/session_manager.dart';
+import 'direct_push_registration.dart';
 import 'nextcloud_push_api.dart';
+import 'push_device_info.dart';
 import 'push_keypair.dart';
 import 'push_registration_store.dart';
 import 'push_registration_type.dart';
@@ -48,8 +50,6 @@ class PushRegistration {
        _store = store ?? const PushRegistrationStore(),
        _nextcloud = nextcloud ?? NextcloudPushApi();
 
-  String get _platform => Platform.isIOS ? 'ios' : 'android';
-
   String get _talkUserAgent =>
       Platform.isIOS ? talkUserAgentIos : talkUserAgentAndroid;
 
@@ -63,20 +63,29 @@ class PushRegistration {
   /// slash) — persisted alongside the registration to detect endpoint changes.
   String get currentNcBaseUrl => 'https://${EndpointData().nextcloud().full()}';
 
+  NextcloudCredentials? get _nextcloudOrNull =>
+      SessionManager().current?.nextcloud;
+
+  /// Channel for sessions without Nextcloud; see [DirectPushRegistration].
+  static const _direct = DirectPushRegistration();
+
   /// Ensures the Nextcloud app password exists (idempotent, best-effort). Push
   /// registration binds to it, so it must be obtained before registering.
   Future<void> ensureAppPassword() async {
-    if (AccountData().hasAppPassword()) return;
-    if (AccountData().usesLoginFlow) {
+    final nextcloud = _nextcloudOrNull;
+    if (nextcloud == null || nextcloud.hasAppPassword) return;
+    if (nextcloud.usesLoginFlow) {
       // Flow-Konten (2FA): Basic Auth mit dem echten Passwort wird abgelehnt,
       // stilles Minting ist unmöglich. Reparatur nur interaktiv über
       // Einstellungen → „Nextcloud neu verbinden".
-      log('Push: login-flow account without app password, cannot mint silently');
+      log(
+        'Push: login-flow account without app password, cannot mint silently',
+      );
       return;
     }
     try {
       final appPassword = await GetAppPassword().run();
-      await AccountData().setAppPassword(appPassword);
+      await SessionManager().setAppPassword(appPassword);
     } on Object catch (e) {
       log('Push: could not obtain app password (non-blocking): $e');
     }
@@ -85,15 +94,16 @@ class PushRegistration {
   /// Ensures the second app password backing the Talk registration exists
   /// (each `getapppassword` call with the real password mints a fresh one).
   Future<void> ensureTalkAppPassword() async {
-    if (AccountData().hasAppPasswordTalk()) return;
+    final nextcloud = _nextcloudOrNull;
+    if (nextcloud == null || nextcloud.hasAppPasswordTalk) return;
     // Flow-Konten können still kein zweites App-Passwort münzen — das
     // Talk-Passwort kommt nur aus dem zweiten Login-Flow-Durchlauf; bis dahin
     // teilt sich die Talk-Registrierung das eine App-Passwort (siehe
-    // AccountData.getTalkBasicAuthHeader).
-    if (AccountData().usesLoginFlow) return;
+    // NextcloudCredentials.talkBasicAuthHeader).
+    if (nextcloud.usesLoginFlow) return;
     try {
       final appPassword = await GetAppPassword().run();
-      await AccountData().setAppPasswordTalk(appPassword);
+      await SessionManager().setAppPasswordTalk(appPassword);
     } on Object catch (e) {
       log('Push: could not obtain talk app password (non-blocking): $e');
     }
@@ -107,6 +117,7 @@ class PushRegistration {
   /// fire-and-forget (and simply ignore the result).
   Future<bool> register() async {
     if (DemoMode.active) return false;
+    if (_nextcloudOrNull == null) return _direct.register();
     final String? fcmToken;
     try {
       fcmToken = await FirebaseMessaging.instance.getToken();
@@ -134,16 +145,13 @@ class PushRegistration {
       return false;
     }
 
-    String? appVersion;
-    try {
-      appVersion = (await PackageInfo.fromPlatform()).version;
-    } on Object {
-      appVersion = null;
-    }
+    final appVersion = await pushAppVersion();
 
+    // Re-read: the ensure* calls above may have swapped the credentials.
+    final nextcloud = SessionManager().requireNextcloud();
     final types = registrationTypesFor(
-      usesLoginFlow: AccountData().usesLoginFlow,
-      hasTalkAppPassword: AccountData().hasAppPasswordTalk(),
+      usesLoginFlow: nextcloud.usesLoginFlow,
+      hasTalkAppPassword: nextcloud.hasAppPasswordTalk,
     );
     if (!types.contains(PushRegistrationType.general)) {
       await _recordAttempt(
@@ -180,7 +188,7 @@ class PushRegistration {
         devicePublicKeyPem: pems.publicKeyPem,
         proxyServer: proxyServer,
         authorizationHeader: isTalk
-            ? AccountData().getTalkBasicAuthHeader()
+            ? SessionManager().requireNextcloud().talkBasicAuthHeader
             : null,
         userAgent: isTalk ? _talkUserAgent : null,
       );
@@ -199,7 +207,7 @@ class PushRegistration {
         deviceIdentifierSignature: registration.signature,
         userPublicKey: registration.publicKey,
         pushToken: fcmToken,
-        platform: _platform,
+        platform: pushPlatform,
         registrationType: type.wireName,
         appVersion: appVersion,
       );
@@ -248,7 +256,7 @@ class PushRegistration {
     try {
       final endpoint = EndpointData().nextcloud();
       await _store.saveNativeAuthContext(
-        username: AccountData().getUsername(),
+        username: SessionManager().requireNextcloud().username,
         baseUrl: 'https://${endpoint.full()}',
       );
     } on Object catch (e) {
@@ -266,7 +274,7 @@ class PushRegistration {
         // session token — each registration with its own app password.
         await _nextcloud.unregister(
           authorizationHeader: type == PushRegistrationType.talk
-              ? AccountData().getTalkBasicAuthHeader()
+              ? SessionManager().requireNextcloud().talkBasicAuthHeader
               : null,
         );
       } on Object catch (e) {
@@ -405,7 +413,9 @@ class PushRegistration {
   static Future<bool> syncSubscription({required bool capable}) async {
     if (!capable) return false;
     if (!await isOsPermissionGranted()) {
-      log('Push: OS notification permission not granted, skipping registration');
+      log(
+        'Push: OS notification permission not granted, skipping registration',
+      );
       return false;
     }
     final registration = PushRegistration();
@@ -429,6 +439,7 @@ class PushRegistration {
   /// pushing before credentials are gone.
   Future<void> logoutCleanup() async {
     if (DemoMode.active) return;
+    if (_nextcloudOrNull == null) return _direct.unregister();
     await unregister();
     try {
       await DeleteAppPassword().run();
@@ -436,15 +447,16 @@ class PushRegistration {
       log('Push: delete app password failed: $e');
     }
     try {
-      if (AccountData().hasAppPasswordTalk()) {
+      final nextcloud = SessionManager().requireNextcloud();
+      if (nextcloud.hasAppPasswordTalk) {
         await DeleteAppPassword().run(
-          authorizationHeader: AccountData().getTalkBasicAuthHeader(),
+          authorizationHeader: nextcloud.talkBasicAuthHeader,
         );
       }
     } on Object catch (e) {
       log('Push: delete talk app password failed: $e');
     }
-    await AccountData().clearAppPassword();
-    await AccountData().clearAppPasswordTalk();
+    await SessionManager().clearAppPassword();
+    await SessionManager().clearAppPasswordTalk();
   }
 }

lib/push/push_registration_store.dart

@@ -24,7 +24,7 @@ class PushRegistrationStore {
   // (reply / mark-as-read) directly via URLSession while the Flutter engine is
   // not guaranteed to run. It needs the Nextcloud username and base URL from the
   // shared (group-scoped) keychain; the app password already lives there
-  // (AccountData writes `nextcloud_app_password` group-scoped).
+  // (SessionManager writes `nextcloud_app_password` group-scoped).
   static const _usernameKey = 'nextcloud_username';
   static const _baseUrlKey = 'nextcloud_base_url';
   // Mirror of the in-app notification toggle (`notificationSettings.enabled`),

lib/push/push_renderer.dart

@@ -12,6 +12,7 @@ import 'nid_store.dart';
 import 'push_actions.dart';
 import 'push_avatar.dart';
 import 'push_subject.dart';
+import 'push_target.dart';
 
 /// Renders decrypted push subjects (and plaintext Connect pushes) as local
 /// notifications. Talk messages of one chat stack into a SINGLE
@@ -23,6 +24,8 @@ class PushRenderer {
   static const talkChannelName = 'Talk-Nachrichten';
   static const generalChannelId = 'nextcloud_general';
   static const generalChannelName = 'Benachrichtigungen';
+  static const parentLettersChannelId = 'parent_letters';
+  static const parentLettersChannelName = 'Elternbriefe';
 
   static const String iosTalkCategory = 'TALK_MESSAGE';
 
@@ -67,6 +70,14 @@ class PushRenderer {
         description: 'Allgemeine Benachrichtigungen',
       ),
     );
+    await android.createNotificationChannel(
+      const AndroidNotificationChannel(
+        parentLettersChannelId,
+        parentLettersChannelName,
+        description: 'Neue Elternbriefe und Antworten der Schule',
+        importance: Importance.high,
+      ),
+    );
   }
 
   /// Renders a decrypted Nextcloud push subject.
@@ -350,23 +361,35 @@ class PushRenderer {
     required String body,
     Map<String, String>? data,
   }) async {
-    final id = _fallbackId('$title$body');
-    const androidDetails = AndroidNotificationDetails(
-      generalChannelId,
-      generalChannelName,
+    final parentLetterId = data?[parentLetterIdKey];
+    final isParentLetter =
+        data?['type'] == parentLetterPushType &&
+        parentLetterId != null &&
+        parentLetterId.isNotEmpty;
+    // One notification per letter: a reply replaces the letter's earlier one.
+    final id = isParentLetter
+        ? parentLetterNotificationId(parentLetterId)
+        : _fallbackId('$title$body');
+    final androidDetails = AndroidNotificationDetails(
+      isParentLetter ? parentLettersChannelId : generalChannelId,
+      isParentLetter ? parentLettersChannelName : generalChannelName,
       importance: Importance.high,
       priority: Priority.high,
       color: _accentColor,
+      styleInformation: isParentLetter ? BigTextStyleInformation(body) : null,
     );
     await _plugin.show(
       id: id,
       title: title,
       body: body,
-      notificationDetails: const NotificationDetails(android: androidDetails),
+      notificationDetails: NotificationDetails(android: androidDetails),
       payload: data == null ? null : jsonEncode(data),
     );
   }
 
+  static int parentLetterNotificationId(String letterId) =>
+      stableChatNotificationId('parent-letter:$letterId');
+
   String _payload({required String? chatToken, required int nid}) =>
       jsonEncode({'chatToken': ?chatToken, 'nid': nid});
 

lib/push/push_secure_storage.dart

@@ -24,7 +24,7 @@ const IOSOptions kPushIosOptions = IOSOptions(
 );
 
 /// Shared secure storage instance for all push key material and registration
-/// bookkeeping. Kept separate from [AccountData]'s default storage because the
+/// bookkeeping. Kept separate from the session's default storage because the
 /// entries here are group-scoped for NSE access.
 const FlutterSecureStorage pushSecureStorage = FlutterSecureStorage(
   iOptions: kPushIosOptions,

lib/push/push_status.dart

@@ -1,7 +1,7 @@
 import 'package:firebase_messaging/firebase_messaging.dart';
 import 'package:flutter/foundation.dart';
 
-import '../model/account_data.dart';
+import '../session/session_manager.dart';
 import 'push_keypair.dart';
 import 'push_registration.dart';
 import 'push_registration_store.dart';
@@ -125,14 +125,15 @@ Future<PushStatusReport> collectPushStatus({
         lastRegistrationError: await store.lastRegistrationError(type),
       );
 
+  final nextcloud = SessionManager().current?.nextcloud;
   return PushStatusReport(
     settingEnabled: settingEnabled,
     osPermission: await _osPermission(),
     serverCapability: !capabilitiesLoaded
         ? PushCheck.unknown
         : (capabilityPush ? PushCheck.ok : PushCheck.fail),
-    appPasswordPresent: AccountData().hasAppPassword(),
-    talkAppPasswordPresent: AccountData().hasAppPasswordTalk(),
+    appPasswordPresent: nextcloud?.hasAppPassword ?? false,
+    talkAppPasswordPresent: nextcloud?.hasAppPasswordTalk ?? false,
     keypairPresent: (await keypair.loadPublicKeyPem())?.isNotEmpty ?? false,
     general: await typeStatus(PushRegistrationType.general),
     talk: await typeStatus(PushRegistrationType.talk),

lib/push/push_tap_router.dart

@@ -1,24 +1,22 @@
 import 'dart:convert';
+import 'dart:developer';
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter_local_notifications/flutter_local_notifications.dart';
 
 import 'push_actions.dart';
+import 'push_target.dart';
 
 /// Routes foreground notification interactions from the single
 /// flutter_local_notifications response callback. Action responses (reply /
 /// mark-read) are dispatched straight to [PushActions]; a plain tap publishes
-/// the target chat token via [pendingChatToken] for [App] to navigate to.
+/// its target via [pendingTarget] for [App] to navigate to.
 class PushTapRouter {
   PushTapRouter._();
 
-  /// Chat token of the most recently tapped Talk notification, or null. [App]
-  /// listens to this and opens the chat, then resets it to null.
-  static final ValueNotifier<String?> pendingChatToken = ValueNotifier(null);
-
-  /// Newsletter id of the most recently tapped Marianum-Message notification,
-  /// or null. [App] listens to this and opens the message, then resets it.
-  static final ValueNotifier<String?> pendingNewsletterId = ValueNotifier(null);
+  /// Target of the most recently tapped notification, or null. [App] listens
+  /// to this and navigates, then resets it to null.
+  static final ValueNotifier<PushTarget?> pendingTarget = ValueNotifier(null);
 
   static void handleResponse(NotificationResponse response) {
     final actionId = response.actionId;
@@ -29,13 +27,28 @@ class PushTapRouter {
     }
     final map = _payloadMap(response.payload);
     if (map == null) return;
-    final newsletterId = _stringValue(map, 'newsletterId');
-    if (newsletterId != null) {
-      pendingNewsletterId.value = newsletterId;
-      return;
+    final target = resolvePushTarget(map);
+    if (target != null) pendingTarget.value = target;
+  }
+
+  static bool _launchHandled = false;
+
+  /// Routes the tap that cold-started the app. The plugin reports such a tap
+  /// only through its launch details, never through the response callback;
+  /// the details stay set for the whole process, hence the one-shot guard.
+  static Future<void> handleAppLaunch(
+    FlutterLocalNotificationsPlugin plugin,
+  ) async {
+    if (_launchHandled) return;
+    _launchHandled = true;
+    try {
+      final details = await plugin.getNotificationAppLaunchDetails();
+      final response = details?.notificationResponse;
+      if (details?.didNotificationLaunchApp != true || response == null) return;
+      handleResponse(response);
+    } on Object catch (e) {
+      log('Reading the notification launch details failed: $e');
     }
-    final token = _stringValue(map, 'chatToken');
-    if (token != null) pendingChatToken.value = token;
   }
 
   static Map<String, dynamic>? _payloadMap(String? payload) {
@@ -46,9 +59,4 @@ class PushTapRouter {
       return null;
     }
   }
-
-  static String? _stringValue(Map<String, dynamic> map, String key) {
-    final value = map[key];
-    return value is String && value.isNotEmpty ? value : null;
-  }
 }

lib/push/push_target.dart

@@ -0,0 +1,45 @@
+/// `type` of the visible Connect push for a parent letter. Its data carries
+/// the letter under [parentLetterIdKey].
+const String parentLetterPushType = 'parent-letter';
+const String parentLetterIdKey = 'parentLetterId';
+
+/// Where a tapped notification leads.
+sealed class PushTarget {
+  const PushTarget();
+}
+
+class ParentLetterTarget extends PushTarget {
+  final String letterId;
+  const ParentLetterTarget(this.letterId);
+}
+
+class NewsletterTarget extends PushTarget {
+  final String newsletterId;
+  const NewsletterTarget(this.newsletterId);
+}
+
+class ChatTarget extends PushTarget {
+  final String chatToken;
+  const ChatTarget(this.chatToken);
+}
+
+/// Resolves the data of a tapped notification — the payload of a locally
+/// rendered one as well as the data of an FCM message. Null when it names no
+/// known target.
+PushTarget? resolvePushTarget(Map<String, dynamic> data) {
+  String? value(String key) {
+    final value = data[key];
+    return value is String && value.isNotEmpty ? value : null;
+  }
+
+  if (value(parentLetterIdKey) case final letterId?) {
+    return ParentLetterTarget(letterId);
+  }
+  if (value('newsletterId') case final newsletterId?) {
+    return NewsletterTarget(newsletterId);
+  }
+  for (final key in const ['chatToken', 'token', 'roomToken']) {
+    if (value(key) case final chatToken?) return ChatTarget(chatToken);
+  }
+  return null;
+}

lib/routing/app_routes.dart

@@ -9,8 +9,8 @@ import '../api/marianumcloud/talk/room/get_room_response.dart';
 import '../api/marianumconnect/marianumconnect_endpoint.dart';
 import '../api/marianumconnect/queries/timetable_get_element_week/timetable_element_type.dart';
 import '../main.dart';
-import '../model/account_data.dart';
 import '../notification/notification_tasks.dart';
+import '../session/session_manager.dart';
 import '../share_intent/pending_share.dart';
 import '../share_intent/remote_file_ref.dart';
 import '../state/app/modules/app_modules.dart';
@@ -26,6 +26,7 @@ import '../view/pages/marianum_message/marianum_message_view.dart';
 import '../view/pages/more/feedback/feedback_dialog.dart';
 import '../view/pages/more/roomplan/roomplan.dart';
 import '../view/pages/more/share/qr_share_view.dart';
+import '../view/pages/parent_letters/parent_letter_view.dart';
 import '../view/pages/settings/chat_background_settings_page.dart';
 import '../view/pages/settings/modules_settings_page.dart';
 import '../view/pages/settings/settings.dart';
@@ -203,6 +204,12 @@ class AppRoutes {
     );
   }
 
+  /// Opens a parent letter by id — from the inbox as well as from push deep
+  /// links, where only the id is known.
+  static void openParentLetter(BuildContext context, {required String id}) {
+    pushScreen(context, withNavBar: false, screen: ParentLetterView(id: id));
+  }
+
   /// Opens a ticker page (CONTENT or PROXIED_FILE) as a standalone detail
   /// screen. Used for deep links from outside the ticker module — inside the
   /// module pages open in-place instead.
@@ -374,7 +381,10 @@ class AppRoutes {
     // ChatBloc._loadChat with the freshly-fetched maxId — sending one
     // here too with the chat list's possibly-stale room.lastMessage.id
     // would race the fresh one and could regress the server cursor.
-    context.read<ChatListBloc>().markRoomAsRead(room.token, room.lastMessage.id);
+    context.read<ChatListBloc>().markRoomAsRead(
+      room.token,
+      room.lastMessage.id,
+    );
     NotificationTasks.clearNotificationsForChat(room.token);
     TalkNavigator.pushSplitView(
       context,
@@ -404,7 +414,8 @@ class AppRoutes {
   static ResolvedPendingChat? resolvePendingChat(BuildContext context) {
     final token = pendingChatToken.value;
     if (token == null) return null;
-    if (!AccountData().isPopulated()) return null;
+    final nextcloud = SessionManager().current?.nextcloud;
+    if (nextcloud == null) return null;
 
     final rooms = context.read<ChatListBloc>().state.data?.rooms;
     final room = _findRoomByToken(rooms, token);
@@ -417,7 +428,7 @@ class AppRoutes {
     );
     return ResolvedPendingChat(
       room: room,
-      selfId: AccountData().getUsername(),
+      selfId: nextcloud.username,
       avatar: avatar,
     );
   }

lib/session/nextcloud_credentials.dart

@@ -0,0 +1,77 @@
+import 'dart:convert';
+
+/// Nextcloud identity of a session. Immutable; the session manager swaps in a
+/// new instance whenever an app password is minted or revoked.
+class NextcloudCredentials {
+  final String username;
+
+  /// The real account password. Invalid against Nextcloud when
+  /// [usesLoginFlow] is set (2FA accounts), where only [appPassword] works.
+  final String password;
+  final String? appPassword;
+
+  /// Backs the second (apptype=talk) push registration — Nextcloud binds each
+  /// push subscription to its session token, so two registrations need two
+  /// app passwords.
+  final String? appPasswordTalk;
+
+  /// True when the credentials came from Login Flow v2 (browser login, e.g.
+  /// because the account has two-factor authentication).
+  final bool usesLoginFlow;
+
+  const NextcloudCredentials({
+    required this.username,
+    required this.password,
+    this.appPassword,
+    this.appPasswordTalk,
+    this.usesLoginFlow = false,
+  });
+
+  bool get hasAppPassword => appPassword != null && appPassword!.isNotEmpty;
+
+  bool get hasAppPasswordTalk =>
+      appPasswordTalk != null && appPasswordTalk!.isNotEmpty;
+
+  /// The app password once available (minted or flow-issued), otherwise the
+  /// real password. It survives real-password rotation and is what the push
+  /// registration is bound to.
+  String get secret => hasAppPassword ? appPassword! : password;
+
+  /// HTTP Basic header value. Prefer headers over credentials in URLs — error
+  /// logs and crash reports often capture the URL but not headers.
+  String get basicAuthHeader => _basicAuth(secret);
+
+  Map<String, String> get authHeaders => {'Authorization': basicAuthHeader};
+
+  /// Authenticates the apptype=talk push registration (and its unregister).
+  /// Throws when the talk password has not been minted yet; callers treat that
+  /// as a failed talk registration and retry on the next start.
+  String get talkBasicAuthHeader {
+    if (hasAppPasswordTalk) return _basicAuth(appPasswordTalk!);
+    // Login-flow account whose second (talk) flow pass was skipped: no silent
+    // minting possible, the talk registration shares the flow credential.
+    if (usesLoginFlow && hasAppPassword) return _basicAuth(appPassword!);
+    throw StateError('Talk app password not available yet');
+  }
+
+  /// Always the real password. Needed to mint the app password via
+  /// `core/getapppassword` — an app password cannot mint another.
+  String get realPasswordBasicAuthHeader => _basicAuth(password);
+
+  NextcloudCredentials copyWith({
+    String? Function()? appPassword,
+    String? Function()? appPasswordTalk,
+    bool? usesLoginFlow,
+  }) => NextcloudCredentials(
+    username: username,
+    password: password,
+    appPassword: appPassword != null ? appPassword() : this.appPassword,
+    appPasswordTalk: appPasswordTalk != null
+        ? appPasswordTalk()
+        : this.appPasswordTalk,
+    usesLoginFlow: usesLoginFlow ?? this.usesLoginFlow,
+  );
+
+  String _basicAuth(String secret) =>
+      'Basic ${base64Encode(utf8.encode('$username:$secret'))}';
+}

lib/session/session.dart

@@ -0,0 +1,74 @@
+import 'dart:convert';
+
+import 'package:crypto/crypto.dart';
+
+import 'nextcloud_credentials.dart';
+
+/// The signed-in account. Exactly one session is active at a time; features
+/// check for the backend identities they need ([nextcloud]) instead of
+/// assuming every account has all of them.
+sealed class Session {
+  /// Local demo session: every backend is served from fixtures (see DemoMode).
+  final bool isDemo;
+
+  const Session({this.isDemo = false});
+
+  /// Nextcloud identity, or null for accounts without one (guardians).
+  NextcloudCredentials? get nextcloud;
+}
+
+/// Student, teacher or staff account: username + password, backed by
+/// MarianumConnect and Nextcloud (with the same username and password).
+final class CredentialSession extends Session {
+  @override
+  final NextcloudCredentials nextcloud;
+
+  CredentialSession({
+    required String username,
+    required String password,
+    String? appPassword,
+    String? appPasswordTalk,
+    bool usesLoginFlow = false,
+    super.isDemo,
+  }) : nextcloud = NextcloudCredentials(
+         username: username,
+         password: password,
+         appPassword: appPassword,
+         appPasswordTalk: appPasswordTalk,
+         usesLoginFlow: usesLoginFlow,
+       );
+
+  const CredentialSession._(this.nextcloud, {super.isDemo});
+
+  String get username => nextcloud.username;
+
+  String get password => nextcloud.password;
+
+  CredentialSession withNextcloud(NextcloudCredentials nextcloud) =>
+      CredentialSession._(nextcloud, isDemo: isDemo);
+
+  /// Legacy MHSL identity (`sha512(user:pass)`), only for the one-off custom
+  /// events migration.
+  String get legacyUserSecret =>
+      sha512.convert(utf8.encode('$username:$password')).toString();
+}
+
+/// Parent/guardian account: passwordless e-mail login, MarianumConnect only.
+final class GuardianSession extends Session {
+  final String email;
+
+  const GuardianSession({required this.email, super.isDemo});
+
+  @override
+  NextcloudCredentials? get nextcloud => null;
+}
+
+/// Thrown when a Nextcloud-only feature is reached with a session that has no
+/// Nextcloud identity. Indicates a missing gate, not a user error.
+class NextcloudUnavailableException implements Exception {
+  const NextcloudUnavailableException();
+
+  @override
+  String toString() =>
+      'NextcloudUnavailableException: session has no Nextcloud account';
+}

lib/session/session_codec.dart

@@ -0,0 +1,70 @@
+import 'session.dart';
+
+/// Keychain keys of the session. Names are frozen: installed versions and the
+/// iOS AppDelegate/NSE read them, so renaming would log every user out.
+abstract final class SessionKeys {
+  static const username = 'username';
+  static const password = 'password';
+  static const appPassword = 'nextcloud_app_password';
+  static const appPasswordTalk = 'nextcloud_app_password_talk';
+  static const loginFlow = 'nextcloud_login_flow';
+  static const demo = 'is_demo';
+
+  // Added with guardian accounts. Absent on installs from before — see
+  // [decodeSession].
+  static const kind = 'session_kind';
+  static const guardianEmail = 'guardian_email';
+
+  static const kindCredential = 'credential';
+  static const kindGuardian = 'guardian';
+}
+
+/// Rebuilds the session from raw keychain values. Installs from before
+/// guardian accounts carry no [SessionKeys.kind]; a stored username and
+/// password then mean a credential session, so existing users stay signed in.
+Session? decodeSession(Map<String, String?> raw) {
+  final isDemo = raw[SessionKeys.demo] == 'true';
+  switch (raw[SessionKeys.kind]) {
+    case SessionKeys.kindGuardian:
+      final email = raw[SessionKeys.guardianEmail];
+      if (email == null || email.isEmpty) return null;
+      return GuardianSession(email: email, isDemo: isDemo);
+    case null:
+    case SessionKeys.kindCredential:
+      final username = raw[SessionKeys.username];
+      final password = raw[SessionKeys.password];
+      if (username == null || password == null) return null;
+      return CredentialSession(
+        username: username,
+        password: password,
+        appPassword: raw[SessionKeys.appPassword],
+        appPasswordTalk: raw[SessionKeys.appPasswordTalk],
+        usesLoginFlow: raw[SessionKeys.loginFlow] == 'true',
+        isDemo: isDemo,
+      );
+    default:
+      // Written by a newer app version; unknown here, treat as signed out.
+      return null;
+  }
+}
+
+/// Keychain values for [session], excluding the group-scoped app passwords
+/// (written separately so the iOS NSE can read them). `null` = delete.
+Map<String, String?> encodeSessionFields(Session session) => switch (session) {
+  CredentialSession() => {
+    SessionKeys.kind: SessionKeys.kindCredential,
+    SessionKeys.username: session.username,
+    SessionKeys.password: session.password,
+    SessionKeys.demo: session.isDemo ? 'true' : null,
+    SessionKeys.loginFlow: session.nextcloud.usesLoginFlow ? 'true' : null,
+    SessionKeys.guardianEmail: null,
+  },
+  GuardianSession() => {
+    SessionKeys.kind: SessionKeys.kindGuardian,
+    SessionKeys.guardianEmail: session.email,
+    SessionKeys.demo: session.isDemo ? 'true' : null,
+    SessionKeys.username: null,
+    SessionKeys.password: null,
+    SessionKeys.loginFlow: null,
+  },
+};

lib/session/session_lifecycle.dart

@@ -0,0 +1,33 @@
+import 'dart:developer';
+
+import 'package:flutter/foundation.dart';
+
+import '../api/marianumconnect/queries/auth_logout/auth_logout.dart';
+import '../auth_link/guardian_link_listener.dart';
+import '../push/push_registration.dart';
+import 'session_manager.dart';
+
+abstract final class SessionLifecycle {
+  /// Why the last sign-out happened, when the user did not ask for it. The
+  /// login screen shows it once and clears it — without it an expired session
+  /// just drops the user on the login screen with no explanation.
+  static final ValueNotifier<String?> signOutNotice = ValueNotifier(null);
+
+  /// Ordered teardown: unregister push and revoke the Nextcloud app passwords
+  /// (while those credentials still exist), then revoke the MC bearer token,
+  /// finally wipe the local session. Each step is best-effort so an offline
+  /// sign-out still reaches a clean local state.
+  static Future<void> signOut({String? notice}) async {
+    signOutNotice.value = notice;
+    try {
+      await PushRegistration().logoutCleanup();
+    } on Object catch (e) {
+      log('Sign-out: push cleanup failed: $e');
+    }
+    await AuthLogout().run();
+    await SessionManager().signOut();
+    // A login link that arrived while signed in must not be replayed on the
+    // login screen that follows.
+    GuardianLinkListener.clear();
+  }
+}

lib/session/session_manager.dart

@@ -0,0 +1,248 @@
+import 'dart:async';
+import 'dart:developer';
+import 'dart:io';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter_secure_storage/flutter_secure_storage.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+import '../push/push_secure_storage.dart';
+import '../utils/exponential_backoff.dart';
+import 'nextcloud_credentials.dart';
+import 'session.dart';
+import 'session_codec.dart';
+
+/// Owns the active [Session] and its persistence. One instance per isolate;
+/// the widget background isolate reads the same keychain.
+class SessionManager {
+  // `first_unlock` so a background launch on a locked device (silent push,
+  // BGAppRefresh) can still read the session. Items written by older versions
+  // carry the plugin default `unlocked` and are invisible to this instance
+  // until _migrateKeychainAccessibility moved them over.
+  static const FlutterSecureStorage _secureStorage = FlutterSecureStorage(
+    iOptions: IOSOptions(accessibility: KeychainAccessibility.first_unlock),
+  );
+  static const FlutterSecureStorage _legacySecureStorage = FlutterSecureStorage(
+    iOptions: IOSOptions(accessibility: KeychainAccessibility.unlocked),
+  );
+  static const List<String> _sessionFields = [
+    SessionKeys.kind,
+    SessionKeys.username,
+    SessionKeys.password,
+    SessionKeys.guardianEmail,
+    SessionKeys.demo,
+    SessionKeys.loginFlow,
+  ];
+
+  static final SessionManager _instance = SessionManager._();
+  factory SessionManager() => _instance;
+
+  SessionManager._() {
+    unawaited(_loadWithRetry());
+  }
+
+  Completer<void> _loaded = Completer();
+  Session? _current;
+
+  Session? get current => _current;
+
+  bool get isSignedIn => _current != null;
+
+  bool get isDemo => _current?.isDemo ?? false;
+
+  /// Whether the session has a Nextcloud identity (Talk, Files, NC push).
+  bool get hasNextcloud => _current?.nextcloud != null;
+
+  /// True once the stored session has been read (or given up on).
+  bool get isLoaded => _loaded.isCompleted;
+
+  /// Resolves once the stored session is known. After [signOut] it stays
+  /// pending until the next sign-in.
+  Future<Session?> waitForLoad() async {
+    await _loaded.future;
+    return _current;
+  }
+
+  /// Stops waiting for the stored session; the app then behaves as signed
+  /// out. The keychain entries stay untouched so a later start can still
+  /// restore the session.
+  void abandonLoad() {
+    if (!_loaded.isCompleted) _loaded.complete();
+  }
+
+  /// Bumped when the server rejects a token that cannot be renewed silently
+  /// (passwordless accounts). The app confirms via [SessionValidator] before
+  /// signing out, so a transient 401 does not cost the session.
+  final ValueNotifier<int> unauthorizedSignal = ValueNotifier(0);
+
+  void reportUnauthorized() => unauthorizedSignal.value++;
+
+  NextcloudCredentials requireNextcloud() =>
+      _current?.nextcloud ?? (throw const NextcloudUnavailableException());
+
+  /// Replaces any stored session completely; no prior [signOut] needed.
+  Future<void> signIn(Session session) async {
+    await Future.wait([
+      for (final MapEntry(:key, :value) in encodeSessionFields(session).entries)
+        _writeSecret(key, value),
+      _writeGroupSecret(
+        SessionKeys.appPassword,
+        session.nextcloud?.appPassword,
+      ),
+      _writeGroupSecret(
+        SessionKeys.appPasswordTalk,
+        session.nextcloud?.appPasswordTalk,
+      ),
+    ]);
+    _current = session;
+    if (!_loaded.isCompleted) _loaded.complete();
+  }
+
+  Future<void> signOut() async {
+    _loaded = Completer();
+    _current = null;
+    await Future.wait([
+      for (final field in _sessionFields) _secureStorage.delete(key: field),
+      _writeGroupSecret(SessionKeys.appPassword, null),
+      _writeGroupSecret(SessionKeys.appPasswordTalk, null),
+    ]);
+  }
+
+  /// Persists a freshly minted Nextcloud app password; from then on every
+  /// Nextcloud call authenticates with it instead of the real password.
+  Future<void> setAppPassword(String appPassword) async {
+    _updateNextcloud((nc) => nc.copyWith(appPassword: () => appPassword));
+    await _writeGroupSecret(SessionKeys.appPassword, appPassword);
+  }
+
+  Future<void> clearAppPassword() async {
+    _updateNextcloud((nc) => nc.copyWith(appPassword: () => null));
+    await _writeGroupSecret(SessionKeys.appPassword, null);
+  }
+
+  /// Adopts an app password obtained via Login Flow v2 and switches the
+  /// account into flow mode. A previously stored Talk app password belonged
+  /// to the old session era and is dropped — the second (optional) flow pass
+  /// stores a fresh one via [setAppPasswordTalk].
+  Future<void> setLoginFlow(String appPassword) async {
+    await setAppPassword(appPassword);
+    await clearAppPasswordTalk();
+    _updateNextcloud((nc) => nc.copyWith(usesLoginFlow: true));
+    await _secureStorage.write(key: SessionKeys.loginFlow, value: 'true');
+  }
+
+  Future<void> setAppPasswordTalk(String appPassword) async {
+    _updateNextcloud((nc) => nc.copyWith(appPasswordTalk: () => appPassword));
+    await _writeGroupSecret(SessionKeys.appPasswordTalk, appPassword);
+  }
+
+  Future<void> clearAppPasswordTalk() async {
+    _updateNextcloud((nc) => nc.copyWith(appPasswordTalk: () => null));
+    await _writeGroupSecret(SessionKeys.appPasswordTalk, null);
+  }
+
+  void _updateNextcloud(
+    NextcloudCredentials Function(NextcloudCredentials) update,
+  ) {
+    final session = _current;
+    if (session is CredentialSession) {
+      _current = session.withNextcloud(update(session.nextcloud));
+    }
+  }
+
+  Future<void> _writeSecret(String key, String? value) => value == null
+      ? _secureStorage.delete(key: key)
+      : _secureStorage.write(key: key, value: value);
+
+  // App passwords live in the push-shared (group-scoped) keystore so the iOS
+  // Notification Service Extension can authenticate Nextcloud calls too. That
+  // keystore may be unavailable (entitlement not provisioned); the in-memory
+  // copy still serves this session.
+  Future<void> _writeGroupSecret(String key, String? value) async {
+    try {
+      if (value == null) {
+        await pushSecureStorage.delete(key: key);
+      } else {
+        await pushSecureStorage.write(key: key, value: value);
+      }
+    } on Object {
+      // ignore — see above
+    }
+  }
+
+  /// iOS keychain reads fail while protected data is unavailable (app launch
+  /// racing the unlock, background wake on a locked device). Without a retry
+  /// the completer never resolved and the app stayed on the launch screen.
+  Future<void> _loadWithRetry() async {
+    for (var attempt = 1; !_loaded.isCompleted; attempt++) {
+      try {
+        await _migrateAndLoad();
+        return;
+      } catch (e, s) {
+        log('Session load failed (attempt $attempt): $e', stackTrace: s);
+        await Future<void>.delayed(exponentialBackoff(attempt));
+      }
+    }
+  }
+
+  Future<void> _migrateAndLoad() async {
+    await _migrateFromLegacyStorage();
+    await _migrateKeychainAccessibility();
+    // On the startup critical path (and every background wake): read in
+    // parallel instead of one keychain round-trip after the other.
+    final values = await Future.wait(
+      _sessionFields.map((field) => _secureStorage.read(key: field)),
+    );
+    final raw = Map<String, String?>.fromIterables(_sessionFields, values);
+    try {
+      final (appPassword, appPasswordTalk) = await (
+        pushSecureStorage.read(key: SessionKeys.appPassword),
+        pushSecureStorage.read(key: SessionKeys.appPasswordTalk),
+      ).wait;
+      raw[SessionKeys.appPassword] = appPassword;
+      raw[SessionKeys.appPasswordTalk] = appPasswordTalk;
+    } on Object {
+      // Group keystore unavailable: fall back to the real password.
+    }
+    _current = decodeSession(raw);
+    if (!_loaded.isCompleted) _loaded.complete();
+  }
+
+  // Move credentials from the old SharedPreferences plain-text storage into the
+  // platform's secure keystore. Run once per install and clear the legacy keys.
+  Future<void> _migrateFromLegacyStorage() async {
+    final prefs = await SharedPreferences.getInstance();
+    final legacyUsername = prefs.getString(SessionKeys.username);
+    final legacyPassword = prefs.getString(SessionKeys.password);
+    if (legacyUsername == null || legacyPassword == null) return;
+
+    final hasSecure =
+        (await _secureStorage.read(key: SessionKeys.username)) != null;
+    if (!hasSecure) {
+      await _secureStorage.write(
+        key: SessionKeys.username,
+        value: legacyUsername,
+      );
+      await _secureStorage.write(
+        key: SessionKeys.password,
+        value: legacyPassword,
+      );
+    }
+    await prefs.remove(SessionKeys.username);
+    await prefs.remove(SessionKeys.password);
+  }
+
+  Future<void> _migrateKeychainAccessibility() async {
+    if (!Platform.isIOS) return;
+    final legacyValues = await Future.wait(
+      _sessionFields.map((field) => _legacySecureStorage.read(key: field)),
+    );
+    for (final (i, field) in _sessionFields.indexed) {
+      final value = legacyValues[i];
+      if (value == null) continue;
+      // Same account+service: the legacy item has to go before the re-add.
+      await _legacySecureStorage.delete(key: field);
+      await _secureStorage.write(key: field, value: value);
+    }
+  }
+}

lib/state/app/infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc.dart

@@ -2,7 +2,9 @@ import 'dart:developer';
 
 import 'package:hydrated_bloc/hydrated_bloc.dart';
 
+import '../../../../../access/access_requirement.dart';
 import '../../../../../api/errors/error_mapper.dart';
+import '../../../../../session/session_manager.dart';
 import '../../loadable_state/loadable_state.dart';
 import '../../loadable_state/loading_error.dart';
 import '../../repository/repository.dart';
@@ -114,6 +116,13 @@ abstract class LoadableHydratedBloc<
     add(Reset<TState>());
   }
 
+  /// Backend identities the data needs. Without them loading is a no-op, so
+  /// reading the bloc in a session that lacks them (e.g. guardians and the
+  /// Nextcloud blocs) is harmless.
+  Set<AccessRequirement> get requirements => const {};
+
+  bool get requirementsMet => requirements.areMetBy(SessionManager().current);
+
   TState? get innerState => state.data;
   TRepository get repo => _repository;
 
@@ -137,6 +146,7 @@ abstract class LoadableHydratedBloc<
   );
 
   void fetch() {
+    if (!requirementsMet) return;
     log('Fetching data for ${TState.toString()}');
     gatherData()
         .catchError((Object e) {

lib/state/app/modules/app_modules.dart

@@ -1,10 +1,12 @@
-import 'package:badges/badges.dart' as badges;
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:persistent_bottom_nav_bar_v2/persistent_bottom_nav_bar_v2.dart';
 
+import '../../../access/access_requirement.dart';
 import '../../../api/marianumconnect/queries/get_breakers/get_breakers_response.dart';
 import '../../../routing/app_routes.dart';
+import '../../../session/session.dart';
+import '../../../session/session_manager.dart';
 import '../../../storage/modules_settings.dart';
 import '../../../view/pages/absence_report/absence_report_view.dart';
 import '../../../view/pages/files/files.dart';
@@ -13,14 +15,18 @@ import '../../../view/pages/holidays/holidays_view.dart';
 import '../../../view/pages/marianum_dates/marianum_dates_view.dart';
 import '../../../view/pages/marianum_message/marianum_message_list_view.dart';
 import '../../../view/pages/more/roomplan/roomplan.dart';
+import '../../../view/pages/parent_letters/parent_letters_view.dart';
 import '../../../view/pages/talk/chat_list.dart';
 import '../../../view/pages/ticker/ticker_view.dart';
 import '../../../view/pages/timetable/timetable.dart';
 import '../../../widget/breaker/breaker.dart';
 import '../../../widget/centered_leading.dart';
+import '../../../widget/module_badge_icon.dart';
 import '../infrastructure/loadable_state/loadable_state.dart';
 import 'chat_list/bloc/chat_list_bloc.dart';
 import 'chat_list/bloc/chat_list_state.dart';
+import 'parent_letters/bloc/parent_letters_bloc.dart';
+import 'parent_letters/bloc/parent_letters_state.dart';
 import 'settings/bloc/settings_cubit.dart';
 
 class AppModule {
@@ -38,6 +44,17 @@ class AppModule {
     required this.create,
   });
 
+  /// Backend identities each module needs. Modules without an entry work for
+  /// every session.
+  static const Map<Modules, Set<AccessRequirement>> requirements = {
+    Modules.talk: {AccessRequirement.nextcloud},
+    Modules.files: {AccessRequirement.nextcloud},
+    Modules.parentLetters: {AccessRequirement.guardian},
+  };
+
+  static bool isAvailableFor(Modules module, Session? session) =>
+      (requirements[module] ?? const {}).areMetBy(session);
+
   static Map<Modules, AppModule> modules(
     BuildContext context, {
     bool showFiltered = false,
@@ -51,6 +68,18 @@ class AppModule {
         breakerArea: BreakerArea.timetable,
         create: Timetable.new,
       ),
+      Modules.parentLetters: AppModule(
+        Modules.parentLetters,
+        name: 'Elternbriefe',
+        icon: () =>
+            BlocBuilder<ParentLettersBloc, LoadableState<ParentLettersState>>(
+              builder: (context, state) => ModuleBadgeIcon(
+                icon: Icons.mail_outline,
+                count: state.data?.unreadCount ?? 0,
+              ),
+            ),
+        create: ParentLettersView.new,
+      ),
       Modules.ticker: AppModule(
         Modules.ticker,
         name: 'Ticker',
@@ -64,34 +93,15 @@ class AppModule {
         Modules.talk,
         name: 'Talk',
         icon: () => BlocBuilder<ChatListBloc, LoadableState<ChatListState>>(
-          builder: (context, state) {
-            final rooms = state.data?.rooms;
-            if (rooms == null || rooms.data.isEmpty) {
-              return const Icon(Icons.chat);
-            }
-            final messages = rooms.data
-                .map((e) => e.unreadMessages)
-                .reduce((a, b) => a + b);
-            return badges.Badge(
-              showBadge: messages > 0,
-              position: badges.BadgePosition.topEnd(top: -3, end: -3),
-              stackFit: StackFit.loose,
-              badgeStyle: badges.BadgeStyle(
-                padding: const EdgeInsets.all(3),
-                badgeColor: Theme.of(context).primaryColor,
-                elevation: 1,
+          builder: (context, state) => ModuleBadgeIcon(
+            icon: Icons.chat,
+            count:
+                state.data?.rooms?.data.fold<int>(
+                  0,
+                  (sum, room) => sum + room.unreadMessages,
+                ) ??
+                0,
           ),
-              badgeContent: Text(
-                '$messages',
-                style: const TextStyle(
-                  color: Colors.white,
-                  fontSize: 10,
-                  fontWeight: FontWeight.bold,
-                ),
-              ),
-              child: const Icon(Icons.chat),
-            );
-          },
         ),
         breakerArea: BreakerArea.talk,
         create: ChatList.new,
@@ -146,6 +156,9 @@ class AppModule {
       ),
     };
 
+    final session = SessionManager().current;
+    available.removeWhere((key, _) => !isAvailableFor(key, session));
+
     if (!showFiltered) {
       available.removeWhere(
         (key, value) =>
@@ -177,9 +190,7 @@ class AppModule {
     for (final missing in Modules.values) {
       if (!seen.add(missing)) continue;
       var insertAt = 0;
-      for (final predecessor in Modules.values.takeWhile(
-        (m) => m != missing,
-      )) {
+      for (final predecessor in Modules.values.takeWhile((m) => m != missing)) {
         final pos = order.indexOf(predecessor);
         if (pos >= insertAt) insertAt = pos + 1;
       }
@@ -285,6 +296,7 @@ class AppModule {
 
 enum Modules {
   timetable,
+  parentLetters,
   ticker,
   talk,
   files,

lib/state/app/modules/capabilities/bloc/capabilities_cubit.dart

@@ -5,6 +5,8 @@ import 'package:hydrated_bloc/hydrated_bloc.dart';
 import '../../../../../api/demo/data/demo_capabilities.dart';
 import '../../../../../api/demo/demo_mode.dart';
 import '../../../../../api/marianumconnect/queries/get_capabilities/get_capabilities.dart';
+import '../../../../../session/session.dart';
+import '../../../../../session/session_manager.dart';
 import 'capabilities_state.dart';
 
 /// Holds the current user's mobile capability flags. Hydrated so the last
@@ -21,17 +23,18 @@ class CapabilitiesCubit extends HydratedCubit<CapabilitiesState> {
 
   int? get timetableFutureDays => state.timetableFutureDays;
 
-  /// Teacher accounts get the class shown on timetable tiles instead of their
-  /// own name (see TimetableAppointmentFactory.showClassInsteadOfTeacher).
-  bool get isTeacher => state.userType == 'TEACHER';
-
   /// Refreshes capabilities from the server. On any failure (endpoint not yet
   /// live, network error, 4xx) the previously hydrated flags are kept but the
-  /// state is marked `loaded` — a failed fetch never silently grants a
-  /// capability, and an offline launch keeps whatever was cached.
+  /// state is marked `loaded` and `loadFailed` — a failed fetch never silently
+  /// grants a capability, an offline launch keeps whatever was cached, and the
+  /// UI can offer a retry instead of claiming a guardian has no children.
   Future<void> load() async {
     if (DemoMode.active) {
-      emit(DemoCapabilities.state());
+      emit(
+        SessionManager().current is GuardianSession
+            ? DemoCapabilities.guardianState()
+            : DemoCapabilities.state(),
+      );
       return;
     }
     try {
@@ -43,16 +46,17 @@ class CapabilitiesCubit extends HydratedCubit<CapabilitiesState> {
           timetablePastDays: response.timetablePastDays,
           timetableFutureDays: response.timetableFutureDays,
           userType: response.userType,
+          children: response.children,
           loaded: true,
         ),
       );
     } catch (e) {
       log('Failed to load capabilities: $e');
-      emit(state.copyWith(loaded: true));
+      emit(state.copyWith(loaded: true, loadFailed: true));
     }
   }
 
-  Future<void> reset() async => emit(const CapabilitiesState());
+  void reset() => emit(const CapabilitiesState());
 
   @override
   CapabilitiesState fromJson(Map<String, dynamic> json) {

lib/state/app/modules/capabilities/bloc/capabilities_state.dart

@@ -1,10 +1,15 @@
 import 'package:freezed_annotation/freezed_annotation.dart';
 
+import '../../../../../access/user_role.dart';
+import '../../../../../api/marianumconnect/queries/get_capabilities/guardian_child.dart';
+
 part 'capabilities_state.freezed.dart';
 part 'capabilities_state.g.dart';
 
 @freezed
 abstract class CapabilitiesState with _$CapabilitiesState {
+  const CapabilitiesState._();
+
   const factory CapabilitiesState({
     @Default(false) bool viewForeignTimetables,
     @Default(false) bool pushNotifications,
@@ -12,14 +17,24 @@ abstract class CapabilitiesState with _$CapabilitiesState {
     // client-side clamp; the (server-narrowed) school year alone governs.
     int? timetablePastDays,
     int? timetableFutureDays,
-    // LDAP user type ('TEACHER' | 'STUDENT' | 'STAFF'); null = unknown.
+    // Wire value of the user type; read it through [role].
     String? userType,
+    // Students a guardian may see; empty for all other accounts.
+    @Default(<GuardianChild>[]) List<GuardianChild> children,
     // Whether a capability response (or a definitive failure) has been
     // observed at least once this session. Lets the UI distinguish "still
     // unknown" from "confirmed not allowed".
     @Default(false) bool loaded,
+    // True while the last attempt failed. Not persisted: a stale failure from
+    // the previous run must not colour a fresh start. Together with [loaded]
+    // it separates "confirmed no children" from "could not ask".
+    @JsonKey(includeToJson: false, includeFromJson: false)
+    @Default(false)
+    bool loadFailed,
   }) = _CapabilitiesState;
 
   factory CapabilitiesState.fromJson(Map<String, Object?> json) =>
       _$CapabilitiesStateFromJson(json);
+
+  UserRole get role => UserRole.parse(userType);
 }

lib/state/app/modules/capabilities/bloc/capabilities_state.freezed.dart

@@ -1,6 +1,6 @@
 // GENERATED CODE - DO NOT MODIFY BY HAND
 // coverage:ignore-file
-// ignore_for_file: type=lint
+// ignore_for_file: type=lint, type=warning, deprecated_member_use, deprecated_member_use_from_same_package
 // ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
 
 part of 'capabilities_state.dart';
@@ -9,19 +9,14 @@ part of 'capabilities_state.dart';
 // FreezedGenerator
 // **************************************************************************
 
+// GENERATED CODE - DO NOT MODIFY BY HAND
 // dart format off
 T _$identity<T>(T value) => value;
 
 /// @nodoc
 mixin _$CapabilitiesState {
 
- bool get viewForeignTimetables; bool get pushNotifications;// Days into the past/future the timetable may be scrolled. Null = no
-// client-side clamp; the (server-narrowed) school year alone governs.
- int? get timetablePastDays; int? get timetableFutureDays;// LDAP user type ('TEACHER' | 'STUDENT' | 'STAFF'); null = unknown.
- String? get userType;// Whether a capability response (or a definitive failure) has been
-// observed at least once this session. Lets the UI distinguish "still
-// unknown" from "confirmed not allowed".
- bool get loaded;
+ bool get viewForeignTimetables; bool get pushNotifications; int? get timetablePastDays; int? get timetableFutureDays; String? get userType; List<GuardianChild> get children; bool get loaded;@JsonKey(includeToJson: false, includeFromJson: false) bool get loadFailed;
 /// Create a copy of CapabilitiesState
 /// with the given fields replaced by the non-null parameter values.
 @JsonKey(includeFromJson: false, includeToJson: false)
@@ -34,16 +29,21 @@ $CapabilitiesStateCopyWith<CapabilitiesState> get copyWith => _$CapabilitiesStat
 
 @override
 bool operator ==(Object other) {
-  return identical(this, other) || (other.runtimeType == runtimeType&&other is CapabilitiesState&&(identical(other.viewForeignTimetables, viewForeignTimetables) || other.viewForeignTimetables == viewForeignTimetables)&&(identical(other.pushNotifications, pushNotifications) || other.pushNotifications == pushNotifications)&&(identical(other.timetablePastDays, timetablePastDays) || other.timetablePastDays == timetablePastDays)&&(identical(other.timetableFutureDays, timetableFutureDays) || other.timetableFutureDays == timetableFutureDays)&&(identical(other.userType, userType) || other.userType == userType)&&(identical(other.loaded, loaded) || other.loaded == loaded));
+  final _this = this as CapabilitiesState;
+  return identical(this, other) || (other.runtimeType == runtimeType&&other is CapabilitiesState&&(identical(other.viewForeignTimetables, _this.viewForeignTimetables) || other.viewForeignTimetables == _this.viewForeignTimetables)&&(identical(other.pushNotifications, _this.pushNotifications) || other.pushNotifications == _this.pushNotifications)&&(identical(other.timetablePastDays, _this.timetablePastDays) || other.timetablePastDays == _this.timetablePastDays)&&(identical(other.timetableFutureDays, _this.timetableFutureDays) || other.timetableFutureDays == _this.timetableFutureDays)&&(identical(other.userType, _this.userType) || other.userType == _this.userType)&&const DeepCollectionEquality().equals(other.children, _this.children)&&(identical(other.loaded, _this.loaded) || other.loaded == _this.loaded)&&(identical(other.loadFailed, _this.loadFailed) || other.loadFailed == _this.loadFailed));
 }
 
 @JsonKey(includeFromJson: false, includeToJson: false)
 @override
-int get hashCode => Object.hash(runtimeType,viewForeignTimetables,pushNotifications,timetablePastDays,timetableFutureDays,userType,loaded);
+int get hashCode {
+  final _this = this as CapabilitiesState;
+  return Object.hash(runtimeType,_this.viewForeignTimetables,_this.pushNotifications,_this.timetablePastDays,_this.timetableFutureDays,_this.userType,const DeepCollectionEquality().hash(_this.children),_this.loaded,_this.loadFailed);
+}
 
 @override
 String toString() {
-  return 'CapabilitiesState(viewForeignTimetables: $viewForeignTimetables, pushNotifications: $pushNotifications, timetablePastDays: $timetablePastDays, timetableFutureDays: $timetableFutureDays, userType: $userType, loaded: $loaded)';
+  final _this = this as CapabilitiesState;
+  return 'CapabilitiesState(viewForeignTimetables: ${_this.viewForeignTimetables}, pushNotifications: ${_this.pushNotifications}, timetablePastDays: ${_this.timetablePastDays}, timetableFutureDays: ${_this.timetableFutureDays}, userType: ${_this.userType}, children: ${_this.children}, loaded: ${_this.loaded}, loadFailed: ${_this.loadFailed})';
 }
 
 
@@ -54,7 +54,7 @@ abstract mixin class $CapabilitiesStateCopyWith<$Res>  {
   factory $CapabilitiesStateCopyWith(CapabilitiesState value, $Res Function(CapabilitiesState) _then) = _$CapabilitiesStateCopyWithImpl;
 @useResult
 $Res call({
- bool viewForeignTimetables, bool pushNotifications, int? timetablePastDays, int? timetableFutureDays, String? userType, bool loaded
+ bool viewForeignTimetables, bool pushNotifications, int? timetablePastDays, int? timetableFutureDays, String? userType, List<GuardianChild> children, bool loaded,@JsonKey(includeToJson: false, includeFromJson: false) bool loadFailed
 });
 
 
@@ -71,14 +71,16 @@ class _$CapabilitiesStateCopyWithImpl<$Res>
 
 /// Create a copy of CapabilitiesState
 /// with the given fields replaced by the non-null parameter values.
-@pragma('vm:prefer-inline') @override $Res call({Object? viewForeignTimetables = null,Object? pushNotifications = null,Object? timetablePastDays = freezed,Object? timetableFutureDays = freezed,Object? userType = freezed,Object? loaded = null,}) {
-  return _then(_self.copyWith(
+@pragma('vm:prefer-inline') @override $Res call({Object? viewForeignTimetables = null,Object? pushNotifications = null,Object? timetablePastDays = freezed,Object? timetableFutureDays = freezed,Object? userType = freezed,Object? children = null,Object? loaded = null,Object? loadFailed = null,}) {
+  return _then(CapabilitiesState(
 viewForeignTimetables: null == viewForeignTimetables ? _self.viewForeignTimetables : viewForeignTimetables // ignore: cast_nullable_to_non_nullable
 as bool,pushNotifications: null == pushNotifications ? _self.pushNotifications : pushNotifications // ignore: cast_nullable_to_non_nullable
 as bool,timetablePastDays: freezed == timetablePastDays ? _self.timetablePastDays : timetablePastDays // ignore: cast_nullable_to_non_nullable
 as int?,timetableFutureDays: freezed == timetableFutureDays ? _self.timetableFutureDays : timetableFutureDays // ignore: cast_nullable_to_non_nullable
 as int?,userType: freezed == userType ? _self.userType : userType // ignore: cast_nullable_to_non_nullable
-as String?,loaded: null == loaded ? _self.loaded : loaded // ignore: cast_nullable_to_non_nullable
+as String?,children: null == children ? _self.children : children // ignore: cast_nullable_to_non_nullable
+as List<GuardianChild>,loaded: null == loaded ? _self.loaded : loaded // ignore: cast_nullable_to_non_nullable
+as bool,loadFailed: null == loadFailed ? _self.loadFailed : loadFailed // ignore: cast_nullable_to_non_nullable
 as bool,
   ));
 }
@@ -164,10 +166,10 @@ return $default(_that);case _:
 /// }
 /// ```
 
-@optionalTypeArgs TResult maybeWhen<TResult extends Object?>(TResult Function( bool viewForeignTimetables,  bool pushNotifications,  int? timetablePastDays,  int? timetableFutureDays,  String? userType,  bool loaded)?  $default,{required TResult orElse(),}) {final _that = this;
+@optionalTypeArgs TResult maybeWhen<TResult extends Object?>(TResult Function( bool viewForeignTimetables,  bool pushNotifications,  int? timetablePastDays,  int? timetableFutureDays,  String? userType,  List<GuardianChild> children,  bool loaded, @JsonKey(includeToJson: false, includeFromJson: false)  bool loadFailed)?  $default,{required TResult orElse(),}) {final _that = this;
 switch (_that) {
 case _CapabilitiesState() when $default != null:
-return $default(_that.viewForeignTimetables,_that.pushNotifications,_that.timetablePastDays,_that.timetableFutureDays,_that.userType,_that.loaded);case _:
+return $default(_that.viewForeignTimetables,_that.pushNotifications,_that.timetablePastDays,_that.timetableFutureDays,_that.userType,_that.children,_that.loaded,_that.loadFailed);case _:
   return orElse();
 
 }
@@ -185,10 +187,10 @@ return $default(_that.viewForeignTimetables,_that.pushNotifications,_that.timeta
 /// }
 /// ```
 
-@optionalTypeArgs TResult when<TResult extends Object?>(TResult Function( bool viewForeignTimetables,  bool pushNotifications,  int? timetablePastDays,  int? timetableFutureDays,  String? userType,  bool loaded)  $default,) {final _that = this;
+@optionalTypeArgs TResult when<TResult extends Object?>(TResult Function( bool viewForeignTimetables,  bool pushNotifications,  int? timetablePastDays,  int? timetableFutureDays,  String? userType,  List<GuardianChild> children,  bool loaded, @JsonKey(includeToJson: false, includeFromJson: false)  bool loadFailed)  $default,) {final _that = this;
 switch (_that) {
 case _CapabilitiesState():
-return $default(_that.viewForeignTimetables,_that.pushNotifications,_that.timetablePastDays,_that.timetableFutureDays,_that.userType,_that.loaded);case _:
+return $default(_that.viewForeignTimetables,_that.pushNotifications,_that.timetablePastDays,_that.timetableFutureDays,_that.userType,_that.children,_that.loaded,_that.loadFailed);case _:
   throw StateError('Unexpected subclass');
 
 }
@@ -205,10 +207,10 @@ return $default(_that.viewForeignTimetables,_that.pushNotifications,_that.timeta
 /// }
 /// ```
 
-@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? Function( bool viewForeignTimetables,  bool pushNotifications,  int? timetablePastDays,  int? timetableFutureDays,  String? userType,  bool loaded)?  $default,) {final _that = this;
+@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? Function( bool viewForeignTimetables,  bool pushNotifications,  int? timetablePastDays,  int? timetableFutureDays,  String? userType,  List<GuardianChild> children,  bool loaded, @JsonKey(includeToJson: false, includeFromJson: false)  bool loadFailed)?  $default,) {final _that = this;
 switch (_that) {
 case _CapabilitiesState() when $default != null:
-return $default(_that.viewForeignTimetables,_that.pushNotifications,_that.timetablePastDays,_that.timetableFutureDays,_that.userType,_that.loaded);case _:
+return $default(_that.viewForeignTimetables,_that.pushNotifications,_that.timetablePastDays,_that.timetableFutureDays,_that.userType,_that.children,_that.loaded,_that.loadFailed);case _:
   return null;
 
 }
@@ -219,22 +221,24 @@ return $default(_that.viewForeignTimetables,_that.pushNotifications,_that.timeta
 /// @nodoc
 @JsonSerializable()
 
-class _CapabilitiesState implements CapabilitiesState {
-  const _CapabilitiesState({this.viewForeignTimetables = false, this.pushNotifications = false, this.timetablePastDays, this.timetableFutureDays, this.userType, this.loaded = false});
+class _CapabilitiesState extends CapabilitiesState {
+  const _CapabilitiesState({this.viewForeignTimetables = false, this.pushNotifications = false, this.timetablePastDays, this.timetableFutureDays, this.userType,  List<GuardianChild> children = const <GuardianChild>[], this.loaded = false, @JsonKey(includeToJson: false, includeFromJson: false) this.loadFailed = false}): _children = children,super._();
   factory _CapabilitiesState.fromJson(Map<String, dynamic> json) => _$CapabilitiesStateFromJson(json);
 
 @override@JsonKey() final  bool viewForeignTimetables;
 @override@JsonKey() final  bool pushNotifications;
-// Days into the past/future the timetable may be scrolled. Null = no
-// client-side clamp; the (server-narrowed) school year alone governs.
 @override final  int? timetablePastDays;
 @override final  int? timetableFutureDays;
-// LDAP user type ('TEACHER' | 'STUDENT' | 'STAFF'); null = unknown.
 @override final  String? userType;
-// Whether a capability response (or a definitive failure) has been
-// observed at least once this session. Lets the UI distinguish "still
-// unknown" from "confirmed not allowed".
+ final  List<GuardianChild> _children;
+@override@JsonKey() List<GuardianChild> get children {
+  if (_children is EqualUnmodifiableListView) return _children;
+  // ignore: implicit_dynamic_type
+  return EqualUnmodifiableListView(_children);
+}
+
 @override@JsonKey() final  bool loaded;
+@override@JsonKey(includeToJson: false, includeFromJson: false) final  bool loadFailed;
 
 /// Create a copy of CapabilitiesState
 /// with the given fields replaced by the non-null parameter values.
@@ -249,16 +253,18 @@ Map<String, dynamic> toJson() {
 
 @override
 bool operator ==(Object other) {
-  return identical(this, other) || (other.runtimeType == runtimeType&&other is _CapabilitiesState&&(identical(other.viewForeignTimetables, viewForeignTimetables) || other.viewForeignTimetables == viewForeignTimetables)&&(identical(other.pushNotifications, pushNotifications) || other.pushNotifications == pushNotifications)&&(identical(other.timetablePastDays, timetablePastDays) || other.timetablePastDays == timetablePastDays)&&(identical(other.timetableFutureDays, timetableFutureDays) || other.timetableFutureDays == timetableFutureDays)&&(identical(other.userType, userType) || other.userType == userType)&&(identical(other.loaded, loaded) || other.loaded == loaded));
+    return identical(this, other) || (other.runtimeType == runtimeType&&other is _CapabilitiesState&&(identical(other.viewForeignTimetables, viewForeignTimetables) || other.viewForeignTimetables == viewForeignTimetables)&&(identical(other.pushNotifications, pushNotifications) || other.pushNotifications == pushNotifications)&&(identical(other.timetablePastDays, timetablePastDays) || other.timetablePastDays == timetablePastDays)&&(identical(other.timetableFutureDays, timetableFutureDays) || other.timetableFutureDays == timetableFutureDays)&&(identical(other.userType, userType) || other.userType == userType)&&const DeepCollectionEquality().equals(other.children, _children)&&(identical(other.loaded, loaded) || other.loaded == loaded)&&(identical(other.loadFailed, loadFailed) || other.loadFailed == loadFailed));
 }
 
 @JsonKey(includeFromJson: false, includeToJson: false)
 @override
-int get hashCode => Object.hash(runtimeType,viewForeignTimetables,pushNotifications,timetablePastDays,timetableFutureDays,userType,loaded);
+int get hashCode {
+    return Object.hash(runtimeType,viewForeignTimetables,pushNotifications,timetablePastDays,timetableFutureDays,userType,const DeepCollectionEquality().hash(_children),loaded,loadFailed);
+}
 
 @override
 String toString() {
-  return 'CapabilitiesState(viewForeignTimetables: $viewForeignTimetables, pushNotifications: $pushNotifications, timetablePastDays: $timetablePastDays, timetableFutureDays: $timetableFutureDays, userType: $userType, loaded: $loaded)';
+    return 'CapabilitiesState(viewForeignTimetables: $viewForeignTimetables, pushNotifications: $pushNotifications, timetablePastDays: $timetablePastDays, timetableFutureDays: $timetableFutureDays, userType: $userType, children: $children, loaded: $loaded, loadFailed: $loadFailed)';
 }
 
 
@@ -269,7 +275,7 @@ abstract mixin class _$CapabilitiesStateCopyWith<$Res> implements $CapabilitiesS
   factory _$CapabilitiesStateCopyWith(_CapabilitiesState value, $Res Function(_CapabilitiesState) _then) = __$CapabilitiesStateCopyWithImpl;
 @override @useResult
 $Res call({
- bool viewForeignTimetables, bool pushNotifications, int? timetablePastDays, int? timetableFutureDays, String? userType, bool loaded
+ bool viewForeignTimetables, bool pushNotifications, int? timetablePastDays, int? timetableFutureDays, String? userType, List<GuardianChild> children, bool loaded,@JsonKey(includeToJson: false, includeFromJson: false) bool loadFailed
 });
 
 
@@ -286,14 +292,16 @@ class __$CapabilitiesStateCopyWithImpl<$Res>
 
 /// Create a copy of CapabilitiesState
 /// with the given fields replaced by the non-null parameter values.
-@override @pragma('vm:prefer-inline') $Res call({Object? viewForeignTimetables = null,Object? pushNotifications = null,Object? timetablePastDays = freezed,Object? timetableFutureDays = freezed,Object? userType = freezed,Object? loaded = null,}) {
+@override @pragma('vm:prefer-inline') $Res call({Object? viewForeignTimetables = null,Object? pushNotifications = null,Object? timetablePastDays = freezed,Object? timetableFutureDays = freezed,Object? userType = freezed,Object? children = null,Object? loaded = null,Object? loadFailed = null,}) {
   return _then(_CapabilitiesState(
 viewForeignTimetables: null == viewForeignTimetables ? _self.viewForeignTimetables : viewForeignTimetables // ignore: cast_nullable_to_non_nullable
 as bool,pushNotifications: null == pushNotifications ? _self.pushNotifications : pushNotifications // ignore: cast_nullable_to_non_nullable
 as bool,timetablePastDays: freezed == timetablePastDays ? _self.timetablePastDays : timetablePastDays // ignore: cast_nullable_to_non_nullable
 as int?,timetableFutureDays: freezed == timetableFutureDays ? _self.timetableFutureDays : timetableFutureDays // ignore: cast_nullable_to_non_nullable
 as int?,userType: freezed == userType ? _self.userType : userType // ignore: cast_nullable_to_non_nullable
-as String?,loaded: null == loaded ? _self.loaded : loaded // ignore: cast_nullable_to_non_nullable
+as String?,children: null == children ? _self._children : children // ignore: cast_nullable_to_non_nullable
+as List<GuardianChild>,loaded: null == loaded ? _self.loaded : loaded // ignore: cast_nullable_to_non_nullable
+as bool,loadFailed: null == loadFailed ? _self.loadFailed : loadFailed // ignore: cast_nullable_to_non_nullable
 as bool,
   ));
 }

lib/state/app/modules/capabilities/bloc/capabilities_state.g.dart

@@ -13,6 +13,11 @@ _CapabilitiesState _$CapabilitiesStateFromJson(Map<String, dynamic> json) =>
       timetablePastDays: (json['timetablePastDays'] as num?)?.toInt(),
       timetableFutureDays: (json['timetableFutureDays'] as num?)?.toInt(),
       userType: json['userType'] as String?,
+      children:
+          (json['children'] as List<dynamic>?)
+              ?.map((e) => GuardianChild.fromJson(e as Map<String, dynamic>))
+              .toList() ??
+          const <GuardianChild>[],
       loaded: json['loaded'] as bool? ?? false,
     );
 
@@ -23,5 +28,6 @@ Map<String, dynamic> _$CapabilitiesStateToJson(_CapabilitiesState instance) =>
       'timetablePastDays': instance.timetablePastDays,
       'timetableFutureDays': instance.timetableFutureDays,
       'userType': instance.userType,
+      'children': instance.children,
       'loaded': instance.loaded,
     };

lib/state/app/modules/chat_list/bloc/chat_list_bloc.dart

@@ -3,6 +3,7 @@ import 'dart:developer';
 
 import 'package:flutter_app_badge/flutter_app_badge.dart';
 
+import '../../../../../access/access_requirement.dart';
 import '../../../../../api/marianumcloud/talk/chat/get_chat_response.dart';
 import '../../../../../api/marianumcloud/talk/room/get_room_response.dart';
 import '../../../infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc.dart';
@@ -43,6 +44,11 @@ class ChatListBloc
     });
   }
 
+  @override
+  Set<AccessRequirement> get requirements => const {
+    AccessRequirement.nextcloud,
+  };
+
   @override
   ChatListRepository repository() => ChatListRepository();
 
@@ -73,6 +79,7 @@ class ChatListBloc
   }
 
   Future<void> refresh({bool renew = true, bool silent = false}) async {
+    if (!requirementsMet) return;
     if (!silent) add(RefetchStarted<ChatListState>());
     Object? capturedError;
     try {

lib/state/app/modules/children/child_selection_cubit.dart

@@ -0,0 +1,33 @@
+import 'package:hydrated_bloc/hydrated_bloc.dart';
+
+import '../../../../api/marianumconnect/queries/get_capabilities/guardian_child.dart';
+
+/// The child a guardian is currently looking at. Shared by every module that
+/// shows per-child data (timetable, absence report, later messages), so
+/// switching the child in one place switches it everywhere.
+class ChildSelectionCubit extends HydratedCubit<String?> {
+  ChildSelectionCubit() : super(null);
+
+  void select(String childId) => emit(childId);
+
+  void reset() => emit(null);
+
+  @override
+  String? fromJson(Map<String, dynamic> json) => json['childId'] as String?;
+
+  @override
+  Map<String, dynamic>? toJson(String? state) => {'childId': state};
+}
+
+/// The selected child if it is still linked, otherwise the first one. Null
+/// when there are no children.
+GuardianChild? effectiveChild(
+  List<GuardianChild> children,
+  String? selectedId,
+) {
+  if (children.isEmpty) return null;
+  for (final child in children) {
+    if (child.id == selectedId) return child;
+  }
+  return children.first;
+}

lib/state/app/modules/foreign_timetable/bloc/foreign_timetable_bloc.dart

@@ -1,204 +0,0 @@
-import 'dart:developer';
-
-import '../../../../../api/marianumconnect/queries/timetable_get_element_week/timetable_element_type.dart';
-import '../../../../../api/marianumconnect/queries/timetable_get_week/timetable_get_week_response.dart';
-import '../../../../../extensions/date_time.dart';
-import '../../../infrastructure/loadable_state/loadable_state.dart';
-import '../../../infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc.dart';
-import '../../../infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc_event.dart';
-import '../../timetable/bloc/timetable_event.dart';
-import '../../timetable/bloc/timetable_state.dart';
-import '../repository/foreign_timetable_repository.dart';
-
-/// Drives a foreign element's timetable. Mirrors `TimetableBloc`'s week-loading
-/// and navigation but loads weeks from the element endpoint, carries no custom
-/// events, and does not persist (page-scoped, recreated per element). Reuses
-/// [TimetableState] verbatim so the render pipeline is unchanged; `customEvents`
-/// stays null (the foreign view's `isReady` predicate ignores it).
-class ForeignTimetableBloc
-    extends
-        LoadableHydratedBloc<
-          TimetableEvent,
-          TimetableState,
-          ForeignTimetableRepository
-        > {
-
-  final TimetableElementType type;
-  // Named `elementId` rather than `id` to avoid shadowing HydratedMixin's
-  // `String get id` (the storage key), which a plain `int id` would illegally
-  // override.
-  final int elementId;
-  final String title;
-
-  DateTime _lastWeekRequestStart = DateTime.fromMillisecondsSinceEpoch(0);
-
-  ForeignTimetableBloc({
-    required this.type,
-    required this.elementId,
-    required this.title,
-  });
-
-  @override
-  ForeignTimetableRepository repository() => ForeignTimetableRepository();
-
-  @override
-  TimetableState fromNothing() {
-    final reference = DateTime.now().addDays(2);
-    return TimetableState(
-      startDate: _startOfWeek(reference),
-      endDate: _endOfWeek(reference),
-    );
-  }
-
-  // Persistence disabled: page-scoped and element-specific, nothing worth
-  // restoring. toJson returns null so nothing is written; fromJson starts fresh.
-  @override
-  Map<String, dynamic>? toJson(LoadableState<TimetableState> state) => null;
-
-  @override
-  LoadableState<TimetableState> fromJson(Map<String, dynamic> json) =>
-      const LoadableState(
-        isLoading: true,
-        data: null,
-        lastFetch: null,
-        reFetch: null,
-        error: null,
-      );
-
-  @override
-  TimetableState fromStorage(Map<String, dynamic> json) => fromNothing();
-
-  @override
-  Map<String, dynamic>? toStorage(TimetableState state) => null;
-
-  @override
-  Future<void> gatherData() async {
-    final initial = innerState ?? fromNothing();
-
-    Object? firstError;
-    void recordError(Object e) {
-      firstError ??= e;
-    }
-
-    await Future.wait([
-      _loadCurrentWeek(initial.startDate, initial.endDate, onError: recordError),
-      _loadStaticReferenceData(onError: recordError),
-    ]);
-
-    if (firstError != null) throw firstError!;
-
-    add(DataGathered((s) => s));
-    _prefetchAdjacentWeeks(initial.startDate, initial.endDate);
-  }
-
-  void changeWeek(DateTime startDate, DateTime endDate) {
-    final current = innerState ?? fromNothing();
-    if (current.startDate == startDate && current.endDate == endDate) return;
-    add(Emit((s) => s.copyWith(startDate: startDate, endDate: endDate)));
-    _loadCurrentWeek(startDate, endDate);
-    _prefetchAdjacentWeeks(startDate, endDate);
-  }
-
-  void resetWeek() {
-    final reference = DateTime.now().addDays(2);
-    changeWeek(_startOfWeek(reference), _endOfWeek(reference));
-  }
-
-  void refresh() => fetch();
-
-  Future<void> _loadCurrentWeek(
-    DateTime startDate,
-    DateTime endDate, {
-    void Function(Object)? onError,
-  }) async {
-    final requestStart = DateTime.now();
-    _lastWeekRequestStart = requestStart;
-    try {
-      final week = await repo.data.getElementWeek(
-        type,
-        elementId,
-        startDate,
-        endDate,
-        onError: onError,
-      );
-      if (_lastWeekRequestStart.isAfter(requestStart)) return;
-      _writeWeekToCache(startDate, week);
-    } catch (e) {
-      log('getElementWeek error for $startDate–$endDate: $e');
-      onError?.call(e);
-    }
-  }
-
-  Future<void> _loadStaticReferenceData({
-    void Function(Object)? onError,
-  }) async {
-    try {
-      final (rooms, subjects, schoolHolidays, schoolyear) = await (
-        repo.data.getRooms(onError: onError),
-        repo.data.getSubjects(onError: onError),
-        repo.data.getSchoolHolidays(onError: onError),
-        repo.data.getCurrentSchoolyear(onError: onError),
-      ).wait;
-
-      add(
-        Emit(
-          (s) => s.copyWith(
-            rooms: rooms,
-            subjects: subjects,
-            schoolHolidays: schoolHolidays,
-            schoolyear: schoolyear,
-            dataVersion: s.dataVersion + 1,
-          ),
-        ),
-      );
-    } catch (e) {
-      onError?.call(e);
-    }
-
-    try {
-      final timegrid = await repo.data.getTimegrid();
-      add(
-        Emit(
-          (s) => s.copyWith(timegrid: timegrid, dataVersion: s.dataVersion + 1),
-        ),
-      );
-    } catch (_) {
-      // Timegrid load failure falls back to a hardcoded schedule in the UI.
-    }
-  }
-
-  void _prefetchAdjacentWeeks(DateTime start, DateTime end) {
-    _prefetchWeek(start.subtractDays(7), end.subtractDays(7));
-    _prefetchWeek(start.addDays(7), end.addDays(7));
-  }
-
-  void _prefetchWeek(DateTime start, DateTime end) {
-    repo.data
-        .getElementWeek(type, elementId, start, end)
-        .then((week) => _writeWeekToCache(start, week))
-        .catchError((_) {});
-  }
-
-  void _writeWeekToCache(DateTime weekStart, TimetableGetWeekResponse week) {
-    final key = weekStart.weekKey();
-    add(
-      Emit((s) {
-        final updated = Map<String, TimetableGetWeekResponse>.of(s.weekCache);
-        updated[key] = week;
-        return s.copyWith(weekCache: updated, dataVersion: s.dataVersion + 1);
-      }),
-    );
-  }
-
-  static DateTime _startOfWeek(DateTime reference) {
-    final monday = reference.subtractDays(reference.weekday - 1);
-    return DateTime(monday.year, monday.month, monday.day);
-  }
-
-  static DateTime _endOfWeek(DateTime reference) {
-    final friday = reference.addDays(
-      DateTime.daysPerWeek - reference.weekday - 2,
-    );
-    return DateTime(friday.year, friday.month, friday.day);
-  }
-}

lib/state/app/modules/foreign_timetable/data_provider/foreign_timetable_data_provider.dart

@@ -1,64 +0,0 @@
-import '../../../../../api/marianumconnect/queries/timetable_get_element_week/timetable_element_type.dart';
-import '../../../../../api/marianumconnect/queries/timetable_get_element_week/timetable_get_element_week.dart';
-import '../../../../../api/marianumconnect/queries/timetable_get_holidays/timetable_get_holidays_response.dart';
-import '../../../../../api/marianumconnect/queries/timetable_get_rooms/timetable_get_rooms_response.dart';
-import '../../../../../api/marianumconnect/queries/timetable_get_schoolyear/timetable_get_schoolyear_response.dart';
-import '../../../../../api/marianumconnect/queries/timetable_get_subjects/timetable_get_subjects_response.dart';
-import '../../../../../api/marianumconnect/queries/timetable_get_timegrid/timetable_get_timegrid_response.dart';
-import '../../../../../api/marianumconnect/queries/timetable_get_week/timetable_get_week_response.dart';
-import '../../timetable/data_provider/timetable_data_provider.dart';
-
-/// Data access for a foreign element's timetable. The week comes from the
-/// element-specific endpoint; all reference data (rooms/subjects/holidays/
-/// school year/timegrid) is school-wide, so it delegates to the existing
-/// [TimetableDataProvider] (which caches it). Custom events are intentionally
-/// absent — they are user-private.
-class ForeignTimetableDataProvider {
-  final TimetableDataProvider _base;
-
-  ForeignTimetableDataProvider([TimetableDataProvider? base])
-    : _base = base ?? TimetableDataProvider();
-
-  Future<TimetableGetWeekResponse> getElementWeek(
-    TimetableElementType type,
-    int id,
-    DateTime startDate,
-    DateTime endDate, {
-    void Function(Object)? onError,
-  }) async {
-    try {
-      return await TimetableGetElementWeek().run(
-        type: type,
-        id: id,
-        from: startDate,
-        until: endDate,
-      );
-    } catch (e) {
-      onError?.call(e);
-      rethrow;
-    }
-  }
-
-  Future<TimetableGetRoomsResponse> getRooms({
-    void Function(Object)? onError,
-    bool renew = false,
-  }) => _base.getRooms(onError: onError, renew: renew);
-
-  Future<TimetableGetSubjectsResponse> getSubjects({
-    void Function(Object)? onError,
-    bool renew = false,
-  }) => _base.getSubjects(onError: onError, renew: renew);
-
-  Future<TimetableGetHolidaysResponse> getSchoolHolidays({
-    void Function(Object)? onError,
-    bool renew = false,
-  }) => _base.getSchoolHolidays(onError: onError, renew: renew);
-
-  Future<TimetableGetSchoolyearResponse> getCurrentSchoolyear({
-    void Function(Object)? onError,
-    bool renew = false,
-  }) => _base.getCurrentSchoolyear(onError: onError, renew: renew);
-
-  Future<TimetableGetTimegridResponse> getTimegrid({bool renew = false}) =>
-      _base.getTimegrid(renew: renew);
-}

lib/state/app/modules/foreign_timetable/repository/foreign_timetable_repository.dart

@@ -1,12 +0,0 @@
-import '../../../infrastructure/repository/repository.dart';
-import '../../timetable/bloc/timetable_state.dart';
-import '../data_provider/foreign_timetable_data_provider.dart';
-
-class ForeignTimetableRepository extends Repository<TimetableState> {
-  final ForeignTimetableDataProvider _provider;
-
-  ForeignTimetableRepository([ForeignTimetableDataProvider? provider])
-    : _provider = provider ?? ForeignTimetableDataProvider();
-
-  ForeignTimetableDataProvider get data => _provider;
-}

lib/state/app/modules/nextcloud_capabilities/bloc/nextcloud_capabilities_cubit.dart

@@ -5,6 +5,7 @@ import 'package:hydrated_bloc/hydrated_bloc.dart';
 import '../../../../../api/demo/data/demo_capabilities.dart';
 import '../../../../../api/demo/demo_mode.dart';
 import '../../../../../api/marianumcloud/capabilities/get_nextcloud_capabilities.dart';
+import '../../../../../session/session_manager.dart';
 import 'nextcloud_capabilities_state.dart';
 
 /// Holds the current user's Nextcloud `files_sharing` capabilities. Hydrated so
@@ -59,6 +60,7 @@ class NextcloudCapabilitiesCubit
   /// Refreshes capabilities from the server. On any failure the previously
   /// hydrated flags are kept but the state is marked `loaded`.
   Future<void> load() async {
+    if (!SessionManager().hasNextcloud) return;
     if (DemoMode.active) {
       emit(DemoNextcloudCapabilities.state());
       return;
@@ -90,7 +92,7 @@ class NextcloudCapabilitiesCubit
     }
   }
 
-  Future<void> reset() async => emit(const NextcloudCapabilitiesState());
+  void reset() => emit(const NextcloudCapabilitiesState());
 
   @override
   NextcloudCapabilitiesState fromJson(Map<String, dynamic> json) {

lib/state/app/modules/parent_letters/bloc/parent_letter_bloc.dart

@@ -0,0 +1,103 @@
+import 'dart:async';
+import 'dart:typed_data';
+
+import '../../../../../api/marianumconnect/queries/parent_letters/parent_letter_exception.dart';
+import '../../../../../api/marianumconnect/queries/parent_letters/parent_letter_models.dart';
+import '../../../../../utils/random_id.dart';
+import '../../../infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc.dart';
+import '../../../infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc_event.dart';
+import '../repository/parent_letter_repository.dart';
+import 'parent_letter_event.dart';
+import 'parent_letter_state.dart';
+import 'parent_letters_bloc.dart';
+
+/// One letter; [id] is the letter id so each letter keeps its own hydrated
+/// cache entry. Changes are mirrored into the app-wide [inbox].
+class ParentLetterBloc
+    extends
+        LoadableHydratedBloc<
+          ParentLetterEvent,
+          ParentLetterState,
+          ParentLetterRepository
+        > {
+  final String letterId;
+  final ParentLettersBloc inbox;
+
+  ParentLetterBloc(this.letterId, {required this.inbox});
+
+  @override
+  String get id => letterId;
+
+  @override
+  Future<void> gatherData() async {
+    final ParentLetterDetail letter;
+    try {
+      letter = await repo.getLetter(letterId);
+    } on ParentLetterException catch (e) {
+      if (e.error == ParentLetterError.letterNotFound) {
+        // Withdrawn: a hydrated copy must not stay readable.
+        add(Emit((state) => state.copyWith(letter: null)));
+        unawaited(inbox.refresh(silent: true));
+      }
+      rethrow;
+    }
+    add(DataGathered((state) => state.copyWith(letter: letter)));
+    if (!letter.summary.read) inbox.markRead(letterId);
+  }
+
+  Future<void> submitResponse({
+    required String childId,
+    required List<ParentLetterAnswer> answers,
+    Uint8List? signaturePng,
+  }) async {
+    final letter = await repo.submitResponse(
+      letterId: letterId,
+      childId: childId,
+      answers: answers,
+      signaturePng: signaturePng,
+    );
+    if (isClosed) return;
+    add(Emit((state) => state.copyWith(letter: letter)));
+    inbox.applyDetail(letter);
+  }
+
+  Future<void> sendThreadMessage(String body) async {
+    final message = await repo.sendThreadMessage(
+      letterId: letterId,
+      body: body,
+      clientMessageId: randomUuidV4(),
+    );
+    if (isClosed) return;
+    add(
+      Emit((state) {
+        final letter = state.letter;
+        if (letter == null) return state;
+        final thread = letter.content.thread;
+        return state.copyWith(
+          letter: ParentLetterDetail(
+            summary: letter.summary,
+            content: letter.content.copyWith(
+              thread: thread.copyWith(messages: [...thread.messages, message]),
+            ),
+          ),
+        );
+      }),
+    );
+  }
+
+  Future<Uint8List> loadAttachment(String attachmentId) =>
+      repo.getAttachment(letterId: letterId, attachmentId: attachmentId);
+
+  @override
+  ParentLetterRepository repository() => ParentLetterRepository();
+
+  @override
+  ParentLetterState fromNothing() => const ParentLetterState();
+
+  @override
+  ParentLetterState fromStorage(Map<String, dynamic> json) =>
+      ParentLetterState.fromJson(json);
+
+  @override
+  Map<String, dynamic>? toStorage(ParentLetterState state) => state.toJson();
+}

lib/state/app/modules/parent_letters/bloc/parent_letter_event.dart

@@ -0,0 +1,5 @@
+import '../../../infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc_event.dart';
+import 'parent_letter_state.dart';
+
+sealed class ParentLetterEvent
+    extends LoadableHydratedBlocEvent<ParentLetterState> {}

lib/state/app/modules/parent_letters/bloc/parent_letter_state.dart

@@ -0,0 +1,15 @@
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+import '../../../../../api/marianumconnect/queries/parent_letters/parent_letter_models.dart';
+
+part 'parent_letter_state.freezed.dart';
+part 'parent_letter_state.g.dart';
+
+@freezed
+abstract class ParentLetterState with _$ParentLetterState {
+  const factory ParentLetterState({ParentLetterDetail? letter}) =
+      _ParentLetterState;
+
+  factory ParentLetterState.fromJson(Map<String, dynamic> json) =>
+      _$ParentLetterStateFromJson(json);
+}

lib/state/app/modules/parent_letters/bloc/parent_letter_state.freezed.dart

@@ -0,0 +1,285 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// coverage:ignore-file
+// ignore_for_file: type=lint, type=warning, deprecated_member_use, deprecated_member_use_from_same_package
+// ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
+
+part of 'parent_letter_state.dart';
+
+// **************************************************************************
+// FreezedGenerator
+// **************************************************************************
+
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// dart format off
+T _$identity<T>(T value) => value;
+
+/// @nodoc
+mixin _$ParentLetterState {
+
+ ParentLetterDetail? get letter;
+/// Create a copy of ParentLetterState
+/// with the given fields replaced by the non-null parameter values.
+@JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+$ParentLetterStateCopyWith<ParentLetterState> get copyWith => _$ParentLetterStateCopyWithImpl<ParentLetterState>(this as ParentLetterState, _$identity);
+
+  /// Serializes this ParentLetterState to a JSON map.
+  Map<String, dynamic> toJson();
+
+
+@override
+bool operator ==(Object other) {
+  final _this = this as ParentLetterState;
+  return identical(this, other) || (other.runtimeType == runtimeType&&other is ParentLetterState&&(identical(other.letter, _this.letter) || other.letter == _this.letter));
+}
+
+@JsonKey(includeFromJson: false, includeToJson: false)
+@override
+int get hashCode {
+  final _this = this as ParentLetterState;
+  return Object.hash(runtimeType,_this.letter);
+}
+
+@override
+String toString() {
+  final _this = this as ParentLetterState;
+  return 'ParentLetterState(letter: ${_this.letter})';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class $ParentLetterStateCopyWith<$Res>  {
+  factory $ParentLetterStateCopyWith(ParentLetterState value, $Res Function(ParentLetterState) _then) = _$ParentLetterStateCopyWithImpl;
+@useResult
+$Res call({
+ ParentLetterDetail? letter
+});
+
+
+
+
+}
+/// @nodoc
+class _$ParentLetterStateCopyWithImpl<$Res>
+    implements $ParentLetterStateCopyWith<$Res> {
+  _$ParentLetterStateCopyWithImpl(this._self, this._then);
+
+  final ParentLetterState _self;
+  final $Res Function(ParentLetterState) _then;
+
+/// Create a copy of ParentLetterState
+/// with the given fields replaced by the non-null parameter values.
+@pragma('vm:prefer-inline') @override $Res call({Object? letter = freezed,}) {
+  return _then(ParentLetterState(
+letter: freezed == letter ? _self.letter : letter // ignore: cast_nullable_to_non_nullable
+as ParentLetterDetail?,
+  ));
+}
+
+}
+
+
+/// Adds pattern-matching-related methods to [ParentLetterState].
+extension ParentLetterStatePatterns on ParentLetterState {
+/// A variant of `map` that fallback to returning `orElse`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeMap<TResult extends Object?>(TResult Function( _ParentLetterState value)?  $default,{required TResult orElse(),}){
+final _that = this;
+switch (_that) {
+case _ParentLetterState() when $default != null:
+return $default(_that);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// Callbacks receives the raw object, upcasted.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case final Subclass2 value:
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult map<TResult extends Object?>(TResult Function( _ParentLetterState value)  $default,){
+final _that = this;
+switch (_that) {
+case _ParentLetterState():
+return $default(_that);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `map` that fallback to returning `null`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? mapOrNull<TResult extends Object?>(TResult? Function( _ParentLetterState value)?  $default,){
+final _that = this;
+switch (_that) {
+case _ParentLetterState() when $default != null:
+return $default(_that);case _:
+  return null;
+
+}
+}
+/// A variant of `when` that fallback to an `orElse` callback.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeWhen<TResult extends Object?>(TResult Function( ParentLetterDetail? letter)?  $default,{required TResult orElse(),}) {final _that = this;
+switch (_that) {
+case _ParentLetterState() when $default != null:
+return $default(_that.letter);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// As opposed to `map`, this offers destructuring.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case Subclass2(:final field2):
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult when<TResult extends Object?>(TResult Function( ParentLetterDetail? letter)  $default,) {final _that = this;
+switch (_that) {
+case _ParentLetterState():
+return $default(_that.letter);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `when` that fallback to returning `null`
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? Function( ParentLetterDetail? letter)?  $default,) {final _that = this;
+switch (_that) {
+case _ParentLetterState() when $default != null:
+return $default(_that.letter);case _:
+  return null;
+
+}
+}
+
+}
+
+/// @nodoc
+@JsonSerializable()
+
+class _ParentLetterState implements ParentLetterState {
+  const _ParentLetterState({this.letter});
+  factory _ParentLetterState.fromJson(Map<String, dynamic> json) => _$ParentLetterStateFromJson(json);
+
+@override final  ParentLetterDetail? letter;
+
+/// Create a copy of ParentLetterState
+/// with the given fields replaced by the non-null parameter values.
+@override @JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+_$ParentLetterStateCopyWith<_ParentLetterState> get copyWith => __$ParentLetterStateCopyWithImpl<_ParentLetterState>(this, _$identity);
+
+@override
+Map<String, dynamic> toJson() {
+  return _$ParentLetterStateToJson(this, );
+}
+
+@override
+bool operator ==(Object other) {
+    return identical(this, other) || (other.runtimeType == runtimeType&&other is _ParentLetterState&&(identical(other.letter, letter) || other.letter == letter));
+}
+
+@JsonKey(includeFromJson: false, includeToJson: false)
+@override
+int get hashCode {
+    return Object.hash(runtimeType,letter);
+}
+
+@override
+String toString() {
+    return 'ParentLetterState(letter: $letter)';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class _$ParentLetterStateCopyWith<$Res> implements $ParentLetterStateCopyWith<$Res> {
+  factory _$ParentLetterStateCopyWith(_ParentLetterState value, $Res Function(_ParentLetterState) _then) = __$ParentLetterStateCopyWithImpl;
+@override @useResult
+$Res call({
+ ParentLetterDetail? letter
+});
+
+
+
+
+}
+/// @nodoc
+class __$ParentLetterStateCopyWithImpl<$Res>
+    implements _$ParentLetterStateCopyWith<$Res> {
+  __$ParentLetterStateCopyWithImpl(this._self, this._then);
+
+  final _ParentLetterState _self;
+  final $Res Function(_ParentLetterState) _then;
+
+/// Create a copy of ParentLetterState
+/// with the given fields replaced by the non-null parameter values.
+@override @pragma('vm:prefer-inline') $Res call({Object? letter = freezed,}) {
+  return _then(_ParentLetterState(
+letter: freezed == letter ? _self.letter : letter // ignore: cast_nullable_to_non_nullable
+as ParentLetterDetail?,
+  ));
+}
+
+
+}
+
+// dart format on

lib/state/app/modules/parent_letters/bloc/parent_letter_state.g.dart

@@ -0,0 +1,17 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'parent_letter_state.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+_ParentLetterState _$ParentLetterStateFromJson(Map<String, dynamic> json) =>
+    _ParentLetterState(
+      letter: json['letter'] == null
+          ? null
+          : ParentLetterDetail.fromJson(json['letter'] as Map<String, dynamic>),
+    );
+
+Map<String, dynamic> _$ParentLetterStateToJson(_ParentLetterState instance) =>
+    <String, dynamic>{'letter': instance.letter};

lib/state/app/modules/parent_letters/bloc/parent_letters_bloc.dart

@@ -0,0 +1,107 @@
+import 'dart:developer';
+
+import '../../../../../access/access_requirement.dart';
+import '../../../../../api/marianumconnect/queries/parent_letters/parent_letter_models.dart';
+import '../../../infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc.dart';
+import '../../../infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc_event.dart';
+import '../parent_letters_logic.dart';
+import '../repository/parent_letters_repository.dart';
+import 'parent_letters_event.dart';
+import 'parent_letters_state.dart';
+
+/// The guardian's letter inbox. Lives app-wide because the module badge and
+/// push handling need it outside the page.
+class ParentLettersBloc
+    extends
+        LoadableHydratedBloc<
+          ParentLettersEvent,
+          ParentLettersState,
+          ParentLettersRepository
+        > {
+  @override
+  Set<AccessRequirement> get requirements => const {AccessRequirement.guardian};
+
+  Future<void>? _loading;
+
+  /// App start, prefetch, page visit and push handling all ask for the first
+  /// page within moments of each other; they share one request.
+  @override
+  Future<void> gatherData() =>
+      _loading ??= _loadFirstPage().whenComplete(() => _loading = null);
+
+  Future<void> _loadFirstPage() async {
+    final page = await repo.getLetters();
+    if (isClosed) return;
+    add(DataGathered((_) => firstPageState(page)));
+  }
+
+  /// Reloads the first page; older pages loaded via [loadOlder] are dropped.
+  Future<void> refresh({bool silent = false}) async {
+    if (!requirementsMet) return;
+    if (!silent) add(RefetchStarted<ParentLettersState>());
+    try {
+      await gatherData();
+    } catch (e) {
+      if (isClosed) return;
+      if (silent) {
+        log('Silent parent letters refresh failed: $e');
+      } else {
+        addLoadingError(e);
+      }
+    }
+  }
+
+  Future<void> loadOlder() async {
+    final letters = innerState?.letters;
+    if (letters == null || letters.isEmpty) return;
+    final page = await repo.getLetters(before: letters.last.id);
+    if (isClosed) return;
+    add(Emit((state) => appendOlderPage(state, page)));
+  }
+
+  /// Optimistic locally. When nothing could be applied locally (a letter
+  /// opened from a push is not in the inbox yet), the follow-up refresh picks
+  /// it up.
+  void markRead(String letterId) {
+    final current = innerState;
+    final updated = current == null ? null : withLetterRead(current, letterId);
+    final appliedLocally = updated != null && !identical(updated, current);
+    if (appliedLocally) add(Emit((_) => updated));
+    repo
+        .markRead(letterId)
+        .then((_) {
+          if (!appliedLocally) _reloadAfterWrite();
+        })
+        .catchError((Object e) {
+          log('Marking parent letter $letterId as read failed: $e');
+          _reloadAfterWrite();
+        });
+  }
+
+  /// A request already in flight may predate the write, so it is not joined.
+  Future<void> _reloadAfterWrite() async {
+    try {
+      await _loading;
+    } on Object {
+      // Its own caller reports the failure.
+    }
+    await refresh(silent: true);
+  }
+
+  /// Takes over a freshly loaded letter.
+  void applyDetail(ParentLetterDetail detail) =>
+      add(Emit((state) => withSummary(state, detail.summary)));
+
+  @override
+  ParentLettersRepository repository() => ParentLettersRepository();
+
+  @override
+  ParentLettersState fromNothing() => const ParentLettersState();
+
+  @override
+  ParentLettersState fromStorage(Map<String, dynamic> json) =>
+      ParentLettersState.fromJson(json);
+
+  @override
+  Map<String, dynamic>? toStorage(ParentLettersState state) => state.toJson();
+}

lib/state/app/modules/parent_letters/bloc/parent_letters_event.dart

@@ -0,0 +1,5 @@
+import '../../../infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc_event.dart';
+import 'parent_letters_state.dart';
+
+sealed class ParentLettersEvent
+    extends LoadableHydratedBlocEvent<ParentLettersState> {}

lib/state/app/modules/parent_letters/bloc/parent_letters_state.dart

@@ -0,0 +1,21 @@
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+import '../../../../../api/marianumconnect/queries/parent_letters/parent_letter_models.dart';
+
+part 'parent_letters_state.freezed.dart';
+part 'parent_letters_state.g.dart';
+
+/// Hydrated inbox. [unreadCount] and [openCount] cover all letters on the
+/// server, not just the loaded [letters].
+@freezed
+abstract class ParentLettersState with _$ParentLettersState {
+  const factory ParentLettersState({
+    @Default([]) List<ParentLetterSummary> letters,
+    @Default(false) bool hasMore,
+    @Default(0) int unreadCount,
+    @Default(0) int openCount,
+  }) = _ParentLettersState;
+
+  factory ParentLettersState.fromJson(Map<String, dynamic> json) =>
+      _$ParentLettersStateFromJson(json);
+}

lib/state/app/modules/parent_letters/bloc/parent_letters_state.freezed.dart

@@ -0,0 +1,300 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// coverage:ignore-file
+// ignore_for_file: type=lint, type=warning, deprecated_member_use, deprecated_member_use_from_same_package
+// ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
+
+part of 'parent_letters_state.dart';
+
+// **************************************************************************
+// FreezedGenerator
+// **************************************************************************
+
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// dart format off
+T _$identity<T>(T value) => value;
+
+/// @nodoc
+mixin _$ParentLettersState {
+
+ List<ParentLetterSummary> get letters; bool get hasMore; int get unreadCount; int get openCount;
+/// Create a copy of ParentLettersState
+/// with the given fields replaced by the non-null parameter values.
+@JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+$ParentLettersStateCopyWith<ParentLettersState> get copyWith => _$ParentLettersStateCopyWithImpl<ParentLettersState>(this as ParentLettersState, _$identity);
+
+  /// Serializes this ParentLettersState to a JSON map.
+  Map<String, dynamic> toJson();
+
+
+@override
+bool operator ==(Object other) {
+  final _this = this as ParentLettersState;
+  return identical(this, other) || (other.runtimeType == runtimeType&&other is ParentLettersState&&const DeepCollectionEquality().equals(other.letters, _this.letters)&&(identical(other.hasMore, _this.hasMore) || other.hasMore == _this.hasMore)&&(identical(other.unreadCount, _this.unreadCount) || other.unreadCount == _this.unreadCount)&&(identical(other.openCount, _this.openCount) || other.openCount == _this.openCount));
+}
+
+@JsonKey(includeFromJson: false, includeToJson: false)
+@override
+int get hashCode {
+  final _this = this as ParentLettersState;
+  return Object.hash(runtimeType,const DeepCollectionEquality().hash(_this.letters),_this.hasMore,_this.unreadCount,_this.openCount);
+}
+
+@override
+String toString() {
+  final _this = this as ParentLettersState;
+  return 'ParentLettersState(letters: ${_this.letters}, hasMore: ${_this.hasMore}, unreadCount: ${_this.unreadCount}, openCount: ${_this.openCount})';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class $ParentLettersStateCopyWith<$Res>  {
+  factory $ParentLettersStateCopyWith(ParentLettersState value, $Res Function(ParentLettersState) _then) = _$ParentLettersStateCopyWithImpl;
+@useResult
+$Res call({
+ List<ParentLetterSummary> letters, bool hasMore, int unreadCount, int openCount
+});
+
+
+
+
+}
+/// @nodoc
+class _$ParentLettersStateCopyWithImpl<$Res>
+    implements $ParentLettersStateCopyWith<$Res> {
+  _$ParentLettersStateCopyWithImpl(this._self, this._then);
+
+  final ParentLettersState _self;
+  final $Res Function(ParentLettersState) _then;
+
+/// Create a copy of ParentLettersState
+/// with the given fields replaced by the non-null parameter values.
+@pragma('vm:prefer-inline') @override $Res call({Object? letters = null,Object? hasMore = null,Object? unreadCount = null,Object? openCount = null,}) {
+  return _then(ParentLettersState(
+letters: null == letters ? _self.letters : letters // ignore: cast_nullable_to_non_nullable
+as List<ParentLetterSummary>,hasMore: null == hasMore ? _self.hasMore : hasMore // ignore: cast_nullable_to_non_nullable
+as bool,unreadCount: null == unreadCount ? _self.unreadCount : unreadCount // ignore: cast_nullable_to_non_nullable
+as int,openCount: null == openCount ? _self.openCount : openCount // ignore: cast_nullable_to_non_nullable
+as int,
+  ));
+}
+
+}
+
+
+/// Adds pattern-matching-related methods to [ParentLettersState].
+extension ParentLettersStatePatterns on ParentLettersState {
+/// A variant of `map` that fallback to returning `orElse`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeMap<TResult extends Object?>(TResult Function( _ParentLettersState value)?  $default,{required TResult orElse(),}){
+final _that = this;
+switch (_that) {
+case _ParentLettersState() when $default != null:
+return $default(_that);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// Callbacks receives the raw object, upcasted.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case final Subclass2 value:
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult map<TResult extends Object?>(TResult Function( _ParentLettersState value)  $default,){
+final _that = this;
+switch (_that) {
+case _ParentLettersState():
+return $default(_that);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `map` that fallback to returning `null`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? mapOrNull<TResult extends Object?>(TResult? Function( _ParentLettersState value)?  $default,){
+final _that = this;
+switch (_that) {
+case _ParentLettersState() when $default != null:
+return $default(_that);case _:
+  return null;
+
+}
+}
+/// A variant of `when` that fallback to an `orElse` callback.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeWhen<TResult extends Object?>(TResult Function( List<ParentLetterSummary> letters,  bool hasMore,  int unreadCount,  int openCount)?  $default,{required TResult orElse(),}) {final _that = this;
+switch (_that) {
+case _ParentLettersState() when $default != null:
+return $default(_that.letters,_that.hasMore,_that.unreadCount,_that.openCount);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// As opposed to `map`, this offers destructuring.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case Subclass2(:final field2):
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult when<TResult extends Object?>(TResult Function( List<ParentLetterSummary> letters,  bool hasMore,  int unreadCount,  int openCount)  $default,) {final _that = this;
+switch (_that) {
+case _ParentLettersState():
+return $default(_that.letters,_that.hasMore,_that.unreadCount,_that.openCount);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `when` that fallback to returning `null`
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? Function( List<ParentLetterSummary> letters,  bool hasMore,  int unreadCount,  int openCount)?  $default,) {final _that = this;
+switch (_that) {
+case _ParentLettersState() when $default != null:
+return $default(_that.letters,_that.hasMore,_that.unreadCount,_that.openCount);case _:
+  return null;
+
+}
+}
+
+}
+
+/// @nodoc
+@JsonSerializable()
+
+class _ParentLettersState implements ParentLettersState {
+  const _ParentLettersState({ List<ParentLetterSummary> letters = const [], this.hasMore = false, this.unreadCount = 0, this.openCount = 0}): _letters = letters;
+  factory _ParentLettersState.fromJson(Map<String, dynamic> json) => _$ParentLettersStateFromJson(json);
+
+ final  List<ParentLetterSummary> _letters;
+@override@JsonKey() List<ParentLetterSummary> get letters {
+  if (_letters is EqualUnmodifiableListView) return _letters;
+  // ignore: implicit_dynamic_type
+  return EqualUnmodifiableListView(_letters);
+}
+
+@override@JsonKey() final  bool hasMore;
+@override@JsonKey() final  int unreadCount;
+@override@JsonKey() final  int openCount;
+
+/// Create a copy of ParentLettersState
+/// with the given fields replaced by the non-null parameter values.
+@override @JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+_$ParentLettersStateCopyWith<_ParentLettersState> get copyWith => __$ParentLettersStateCopyWithImpl<_ParentLettersState>(this, _$identity);
+
+@override
+Map<String, dynamic> toJson() {
+  return _$ParentLettersStateToJson(this, );
+}
+
+@override
+bool operator ==(Object other) {
+    return identical(this, other) || (other.runtimeType == runtimeType&&other is _ParentLettersState&&const DeepCollectionEquality().equals(other.letters, _letters)&&(identical(other.hasMore, hasMore) || other.hasMore == hasMore)&&(identical(other.unreadCount, unreadCount) || other.unreadCount == unreadCount)&&(identical(other.openCount, openCount) || other.openCount == openCount));
+}
+
+@JsonKey(includeFromJson: false, includeToJson: false)
+@override
+int get hashCode {
+    return Object.hash(runtimeType,const DeepCollectionEquality().hash(_letters),hasMore,unreadCount,openCount);
+}
+
+@override
+String toString() {
+    return 'ParentLettersState(letters: $letters, hasMore: $hasMore, unreadCount: $unreadCount, openCount: $openCount)';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class _$ParentLettersStateCopyWith<$Res> implements $ParentLettersStateCopyWith<$Res> {
+  factory _$ParentLettersStateCopyWith(_ParentLettersState value, $Res Function(_ParentLettersState) _then) = __$ParentLettersStateCopyWithImpl;
+@override @useResult
+$Res call({
+ List<ParentLetterSummary> letters, bool hasMore, int unreadCount, int openCount
+});
+
+
+
+
+}
+/// @nodoc
+class __$ParentLettersStateCopyWithImpl<$Res>
+    implements _$ParentLettersStateCopyWith<$Res> {
+  __$ParentLettersStateCopyWithImpl(this._self, this._then);
+
+  final _ParentLettersState _self;
+  final $Res Function(_ParentLettersState) _then;
+
+/// Create a copy of ParentLettersState
+/// with the given fields replaced by the non-null parameter values.
+@override @pragma('vm:prefer-inline') $Res call({Object? letters = null,Object? hasMore = null,Object? unreadCount = null,Object? openCount = null,}) {
+  return _then(_ParentLettersState(
+letters: null == letters ? _self._letters : letters // ignore: cast_nullable_to_non_nullable
+as List<ParentLetterSummary>,hasMore: null == hasMore ? _self.hasMore : hasMore // ignore: cast_nullable_to_non_nullable
+as bool,unreadCount: null == unreadCount ? _self.unreadCount : unreadCount // ignore: cast_nullable_to_non_nullable
+as int,openCount: null == openCount ? _self.openCount : openCount // ignore: cast_nullable_to_non_nullable
+as int,
+  ));
+}
+
+
+}
+
+// dart format on

lib/state/app/modules/parent_letters/bloc/parent_letters_state.g.dart

@@ -0,0 +1,29 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'parent_letters_state.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+_ParentLettersState _$ParentLettersStateFromJson(Map<String, dynamic> json) =>
+    _ParentLettersState(
+      letters:
+          (json['letters'] as List<dynamic>?)
+              ?.map(
+                (e) => ParentLetterSummary.fromJson(e as Map<String, dynamic>),
+              )
+              .toList() ??
+          const [],
+      hasMore: json['hasMore'] as bool? ?? false,
+      unreadCount: (json['unreadCount'] as num?)?.toInt() ?? 0,
+      openCount: (json['openCount'] as num?)?.toInt() ?? 0,
+    );
+
+Map<String, dynamic> _$ParentLettersStateToJson(_ParentLettersState instance) =>
+    <String, dynamic>{
+      'letters': instance.letters,
+      'hasMore': instance.hasMore,
+      'unreadCount': instance.unreadCount,
+      'openCount': instance.openCount,
+    };

lib/state/app/modules/parent_letters/parent_letters_logic.dart

@@ -0,0 +1,67 @@
+import '../../../../api/marianumconnect/queries/parent_letters/parent_letter_models.dart';
+import 'bloc/parent_letters_state.dart';
+
+ParentLettersState firstPageState(ParentLetterListResponse page) =>
+    ParentLettersState(
+      letters: page.items,
+      hasMore: page.hasMore,
+      unreadCount: page.unreadCount,
+      openCount: page.openCount,
+    );
+
+ParentLettersState appendOlderPage(
+  ParentLettersState state,
+  ParentLetterListResponse page,
+) {
+  final known = {for (final letter in state.letters) letter.id};
+  return state.copyWith(
+    letters: [
+      ...state.letters,
+      ...page.items.where((letter) => !known.contains(letter.id)),
+    ],
+    hasMore: page.hasMore,
+    unreadCount: page.unreadCount,
+    openCount: page.openCount,
+  );
+}
+
+/// Marks [letterId] as read and lowers the unread counter. Returns [state]
+/// itself when the letter is unknown or already read.
+ParentLettersState withLetterRead(ParentLettersState state, String letterId) {
+  final index = state.letters.indexWhere((letter) => letter.id == letterId);
+  if (index < 0 || state.letters[index].read) return state;
+  final letters = [...state.letters];
+  letters[index] = letters[index].copyWith(read: true);
+  return state.copyWith(
+    letters: letters,
+    unreadCount: state.unreadCount > 0 ? state.unreadCount - 1 : 0,
+  );
+}
+
+/// Replaces the letter and moves [ParentLettersState.openCount] along with
+/// its status, so answering does not need a reload to fix the counter.
+ParentLettersState withSummary(
+  ParentLettersState state,
+  ParentLetterSummary summary,
+) {
+  final index = state.letters.indexWhere((letter) => letter.id == summary.id);
+  if (index < 0) return state;
+  int open(ParentLetterSummary letter) =>
+      letter.status == ParentLetterStatus.open ? 1 : 0;
+  final openCount =
+      state.openCount - open(state.letters[index]) + open(summary);
+  final letters = [...state.letters];
+  letters[index] = summary;
+  return state.copyWith(
+    letters: letters,
+    openCount: openCount < 0 ? 0 : openCount,
+  );
+}
+
+/// [childId] null means all children.
+List<ParentLetterSummary> filterLettersByChild(
+  List<ParentLetterSummary> letters,
+  String? childId,
+) => childId == null
+    ? letters
+    : letters.where((letter) => letter.childIds.contains(childId)).toList();