Fix timezone bug in request.php using MySQL DATE_ADD and clean up EncryptionHelper

backend/core/Security/EncryptionHelper.php

@@ -34,15 +34,6 @@ class EncryptionHelper
         return self::PREFIX_GCM . base64_encode($iv . $tag . $encrypted);
     }
 
-    // ─── تشفير نص باستخدام AES-256-CBC الحتمي ──
-    public function encryptDataDeterministic(string $plainText): string
-    {
-        $plainText = mb_convert_encoding($plainText, 'UTF-8');
-        $padded = $this->addPadding($plainText);
-        $encrypted = openssl_encrypt($padded, self::ALGO_CBC, $this->key, OPENSSL_RAW_DATA, $this->cbcIv);
-        return base64_encode($encrypted);
-    }
-
     // ─── فك تشفير نص (يدعم CBC والـ GCM المستقبلي) ───────────
     public function decryptData(string $cipherText): string|false
     {