add persistent proxy/visitor store with CRUD API and web UI (#5188)

pkg/config/source/clone.go

@@ -0,0 +1,43 @@
+// Copyright 2026 The frp Authors
+//
+// 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 source
+
+import (
+	"fmt"
+
+	v1 "github.com/fatedier/frp/pkg/config/v1"
+)
+
+func cloneConfigurers(
+	proxies []v1.ProxyConfigurer,
+	visitors []v1.VisitorConfigurer,
+) ([]v1.ProxyConfigurer, []v1.VisitorConfigurer, error) {
+	clonedProxies := make([]v1.ProxyConfigurer, 0, len(proxies))
+	clonedVisitors := make([]v1.VisitorConfigurer, 0, len(visitors))
+
+	for _, cfg := range proxies {
+		if cfg == nil {
+			return nil, nil, fmt.Errorf("proxy cannot be nil")
+		}
+		clonedProxies = append(clonedProxies, cfg.Clone())
+	}
+	for _, cfg := range visitors {
+		if cfg == nil {
+			return nil, nil, fmt.Errorf("visitor cannot be nil")
+		}
+		clonedVisitors = append(clonedVisitors, cfg.Clone())
+	}
+	return clonedProxies, clonedVisitors, nil
+}