refactor: implement all core services

examples/relay/RelayService.h

@@ -0,0 +1,25 @@
+#pragma once
+#include "Service.h"
+#include "TaskManager.h"
+#include <ArduinoJson.h>
+
+class RelayService : public Service {
+public:
+    RelayService(TaskManager& taskMgr, int pin);
+    void registerEndpoints(ApiServer& api) override;
+    const char* getName() const override { return "Relay"; }
+
+    void turnOn();
+    void turnOff();
+    void toggle();
+
+private:
+    void registerTasks();
+
+    TaskManager& taskManager;
+    int relayPin;
+    bool relayOn;
+
+    void handleStatusRequest(AsyncWebServerRequest* request);
+    void handleControlRequest(AsyncWebServerRequest* request);
+};