feat: login api

lib/domain/auth/entities/auth_entity.dart

@@ -0,0 +1,18 @@
+part of '../auth.dart';
+
+@freezed
+class Auth with _$Auth {
+  const Auth._();
+  const factory Auth({
+    required String token,
+    required DateTime expiresAt,
+    required User user,
+  }) = _Auth;
+
+  /// State kosong (misalnya untuk initial state di Bloc)
+  factory Auth.empty() => Auth(
+    token: '',
+    expiresAt: DateTime.fromMillisecondsSinceEpoch(0),
+    user: User.empty(),
+  );
+}