Enhance HardwareRfid class with detailed logging and hardware verification; update main loop to log detected RFID tags

lib/hardware/hardware_rfid.hpp

@@ -1,13 +1,22 @@
 #pragma once
 
-#include <MFRC522.h>
-#include <functional>
 #include "hardware.pb.h"
+#include <MFRC522.h>
 
-typedef std::function<void(const hardware_SensorToControlMessage&)> RfidCallback;
-
+/**
+ * @class HardwareRfid
+ * @brief Manages an MFRC522 RFID reader on ESP8266.
+ * Reads card UIDs and sends them via a callback using hardware_SensorToControlMessage.
+ */
 class HardwareRfid {
 public:
+    using RfidCallback = void (*)(const hardware_SensorToControlMessage&);
+
+    /**
+     * @brief Constructor for HardwareRfid.
+     * @param ssPin SPI Slave Select (SS) pin for MFRC522.
+     * @param rstPin Reset pin for MFRC522.
+     */
     HardwareRfid(uint8_t ssPin, uint8_t rstPin);
     void begin();
     void end();
@@ -16,5 +25,5 @@ public:
 
 private:
     MFRC522 _mfrc;
-    RfidCallback _callback;
-};
+    RfidCallback _callback = nullptr;
+};