Remove turn signal & sonar, add RFID auth

Define AUTH_UID and AUTH_UID_SIZE constants.
Introduce motor control pins IN_1‑IN_4 and set them as outputs.
Comment out turn‑signal and sonar pin definitions and related code.
Refactor Display to remove updateDirection functionality.
Extend RFIDReader with reset() and matches() methods; use them to toggle
carEnabled based on RFID authentication.
Update the main loop to operate only when the RFID tag matches the
authorized UID.

RFID.cpp

@@ -11,18 +11,30 @@ void RFIDReader::begin() {
 bool RFIDReader::check() {
   if (!_rfid.PICC_IsNewCardPresent()) return false;
   if (!_rfid.PICC_ReadCardSerial()) return false;
+  // _rfid.PICC_HaltA();          // stop the tag
+  // _rfid.PCD_StopCrypto1();     // clear RC522 crypto
+  return true;
+}
 
+void RFIDReader::reset() {
   _rfid.PICC_HaltA();
+  _rfid.PCD_StopCrypto1();
+}
+
+bool RFIDReader::matches(const byte* expectedUid, byte expectedSize) const {
+  if (_rfid.uid.size != expectedSize) return false;
+  for (byte i = 0; i < expectedSize; ++i) {
+    if (_rfid.uid.uidByte[i] != expectedUid[i]) return false;
+  }
   return true;
 }
 
 void RFIDReader::printUID() const {
-  Serial.print(F("RFID Tag UID:"));
-  for (byte i = 0; i < _rfid.uid.size; i++) {
-    Serial.print(_rfid.uid.uidByte[i] < 0x10 ? " 0" : " ");
-    Serial.print(_rfid.uid.uidByte[i], HEX);
-  }
-  Serial.println();
+  Serial.println(F("RFID Tag UID:"));
+  // for (byte i = 0; i < _rfid.uid.size; i++) {
+  //   Serial.print(_rfid.uid.uidByte[i] < 0x10 ? " 0" : " ");
+  //   Serial.print(_rfid.uid.uidByte[i], HEX);
+  // }
 }
 
 const byte* RFIDReader::getUID() const {