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

pkg/config/source/config_source.go

@@ -0,0 +1,65 @@
+// 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"
+)
+
+// ConfigSource implements Source for in-memory configuration.
+// All operations are thread-safe.
+type ConfigSource struct {
+	baseSource
+}
+
+func NewConfigSource() *ConfigSource {
+	return &ConfigSource{
+		baseSource: newBaseSource(),
+	}
+}
+
+// ReplaceAll replaces all proxy and visitor configurations atomically.
+func (s *ConfigSource) ReplaceAll(proxies []v1.ProxyConfigurer, visitors []v1.VisitorConfigurer) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	nextProxies := make(map[string]v1.ProxyConfigurer, len(proxies))
+	for _, p := range proxies {
+		if p == nil {
+			return fmt.Errorf("proxy cannot be nil")
+		}
+		name := p.GetBaseConfig().Name
+		if name == "" {
+			return fmt.Errorf("proxy name cannot be empty")
+		}
+		nextProxies[name] = p
+	}
+	nextVisitors := make(map[string]v1.VisitorConfigurer, len(visitors))
+	for _, v := range visitors {
+		if v == nil {
+			return fmt.Errorf("visitor cannot be nil")
+		}
+		name := v.GetBaseConfig().Name
+		if name == "" {
+			return fmt.Errorf("visitor name cannot be empty")
+		}
+		nextVisitors[name] = v
+	}
+	s.proxies = nextProxies
+	s.visitors = nextVisitors
+	return nil
+}