replaced account data singleton with a session model

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_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/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:shared_preferences/shared_preferences.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';
@@ -26,28 +26,32 @@ class CustomEventsMigration {
   const CustomEventsMigration._();
 
   static Future<void> runOnce() async {
-    if (DemoMode.active) return;
+    // Only password accounts can derive the legacy identity.
+    final session = SessionManager().current;
+    if (session is! CredentialSession || session.isDemo) return;
     if (await _isDone()) return;
 
-    final epoch = AccountData().sessionEpoch;
+    final epoch = SessionManager().sessionEpoch;
     try {
       final response = await GetCustomTimetableEvent(
-        GetCustomTimetableEventParams(AccountData().getUserSecret()),
+        GetCustomTimetableEventParams(session.legacyUserSecret),
       ).run();
 
       for (final event in response.events) {
         // The POST authenticates with whoever is signed in now; after a
         // sign-out the previous account's events would land in the next one.
-        if (!AccountData().isCurrentSession(epoch)) return;
+        if (!SessionManager().isCurrentSession(epoch)) return;
         await TimetableCustomEventsAdd().run(event);
         await RemoveCustomTimetableEvent(
           RemoveCustomTimetableEventParams(event.id),
         ).run();
       }
 
-      if (!AccountData().isCurrentSession(epoch)) return;
+      if (!SessionManager().isCurrentSession(epoch)) return;
       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.