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.

Display.h

@@ -19,7 +19,7 @@ public:
 
   void updateGear(char gearChar);
 
-  void updateDirection(bool leftOn, bool rightOn);
+  // void updateDirection(bool leftOn, bool rightOn);
 
 private:
   rgb_lcd _lcd;