fix: add Detector interface (#1629)

Author: knyk-dev

detector/detector.go

@@ -0,0 +1,25 @@
+// Copyright 2025 The casbin Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package detector
+
+import "github.com/casbin/casbin/v3/rbac"
+
+// Detector defines the interface of a policy consistency checker, currently used to detect RBAC inheritance cycles.
+type Detector interface {
+	// Check checks whether the current status of the passed-in RoleManager contains logical errors (e.g., cycles in role inheritance).
+	// param: rm RoleManager instance
+	// return: If an error is found, return a descriptive error; otherwise return nil.
+	Check(rm rbac.RoleManager) error
+}