refactor: service folder structure

include/services/ClusterService.h

@@ -0,0 +1,16 @@
+#pragma once
+#include "services/Service.h"
+#include "NodeContext.h"
+#include <ArduinoJson.h>
+
+class ClusterService : public Service {
+public:
+    ClusterService(NodeContext& ctx);
+    void registerEndpoints(ApiServer& api) override;
+    const char* getName() const override { return "Cluster"; }
+
+private:
+    NodeContext& ctx;
+    
+    void handleMembersRequest(AsyncWebServerRequest* request);
+};