persist login securely

lib/models/session_backup.dart

@@ -0,0 +1,17 @@
+import "package:freezed_annotation/freezed_annotation.dart";
+part "session_backup.freezed.dart";
+part "session_backup.g.dart";
+
+@freezed
+abstract class SessionBackup with _$SessionBackup {
+  const factory SessionBackup({
+    required String accessToken,
+    required Uri homeserver,
+    required String userID,
+    required String deviceID,
+    required String deviceName,
+  }) = _SessionBackup;
+
+  factory SessionBackup.fromJson(Map<String, Object?> json) =>
+      _$SessionBackupFromJson(json);
+}