add auth register

lib/features/auth/domain/entities/customer_group.dart

@@ -0,0 +1,60 @@
+/// Domain Entity: Customer Group (Role)
+///
+/// Represents a customer group/role for user registration.
+library;
+
+/// Customer Group Entity
+class CustomerGroup {
+  /// Unique identifier
+  final String name;
+
+  /// Display name
+  final String customerGroupName;
+
+  /// Group value/code
+  final String? value;
+
+  const CustomerGroup({
+    required this.name,
+    required this.customerGroupName,
+    this.value,
+  });
+
+  /// Create from JSON map
+  factory CustomerGroup.fromJson(Map<String, dynamic> json) {
+    return CustomerGroup(
+      name: json['name'] as String,
+      customerGroupName: json['customer_group_name'] as String,
+      value: json['value'] as String?,
+    );
+  }
+
+  /// Convert to JSON map
+  Map<String, dynamic> toJson() {
+    return {
+      'name': name,
+      'customer_group_name': customerGroupName,
+      if (value != null) 'value': value,
+    };
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) return true;
+
+    return other is CustomerGroup &&
+        other.name == name &&
+        other.customerGroupName == customerGroupName &&
+        other.value == value;
+  }
+
+  @override
+  int get hashCode {
+    return Object.hash(name, customerGroupName, value);
+  }
+
+  @override
+  String toString() {
+    return 'CustomerGroup(name: $name, customerGroupName: $customerGroupName, value: $value)';
+  }
+}