added guardian login with views for their assigned childs

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}/';
 }