Fix Database getInstance method and connection call

backend/app/Core/Database.php

@@ -13,18 +13,23 @@ class Database
     private static ?PDO $instance = null;
 
     /**
-     * Get active PDO database instance
+     * Get active PDO database instance (alias or direct connection)
      *
      * @return PDO
      * @throws PDOException
      */
+    public static function getInstance(): PDO
+    {
+        return self::getConnection();
+    }
+
     public static function getConnection(): PDO
     {
         if (self::$instance === null) {
             $host = getenv('DB_HOST') ?: '127.0.0.1';
             $port = getenv('DB_PORT') ?: '3306';
-            $dbName = getenv('DB_DATABASE') ?: 'nabeh_master';
-            $username = getenv('DB_USERNAME') ?: 'root';
+            $dbName = getenv('DB_DATABASE') ?: 'saqelDB';
+            $username = getenv('DB_USERNAME') ?: 'saqelUser';
             $password = getenv('DB_PASSWORD') ?: '';
 
             $dsn = "mysql:host={$host};port={$port};dbname={$dbName};charset=utf8mb4";

backend/public/migrate.php

@@ -7,7 +7,7 @@ use App\Core\Database;
 header('Content-Type: application/json; charset=utf-8');
 
 try {
-    $db = Database::getInstance()->getConnection();
+    $db = Database::getConnection();
     
     // Disable Foreign Key checks explicitly on the active connection
     $db->exec("SET FOREIGN_KEY_CHECKS = 0;");