WIP auth, added Drift for database and refined shared_models for data exchange

shared_models/lib/user.dart

@@ -0,0 +1,31 @@
+import 'package:json_annotation/json_annotation.dart';
+
+part 'user.g.dart';
+
+@JsonSerializable()
+class User {
+  final String id;
+  final String name;
+  final String? roomId;
+
+  User({
+    required this.id,
+    required this.name,
+    this.roomId,
+  });
+
+  factory User.fromJson(Map<String, dynamic> json) => _$UserFromJson(json);
+
+  Map<String, dynamic> toJson() => _$UserToJson(this);
+}
+
+@JsonSerializable()
+class CreateUserRequest {
+  final String username;
+
+  CreateUserRequest({required this.username});
+
+  factory CreateUserRequest.fromJson(Map<String, dynamic> json) => _$CreateUserRequestFromJson(json);
+
+  Map<String, dynamic> toJson() => _$CreateUserRequestToJson(this);
+}