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.h

@@ -10,8 +10,12 @@ public:
 
   bool check();
 
+  void reset();
+
   void printUID() const;
 
+  bool matches(const byte* expectedUid, byte expectedSize) const;
+
   const byte* getUID() const;
   byte getUIDSize() const;