Update -> refactor and optimize UI , code ,...

app/core/db.php

@@ -1,13 +1,21 @@
 <?php
 $config = require __DIR__ . '/../config/config.php';
+
 try {
-    $pdo = new PDO(
-        "mysql:host={$config['db']['host']};dbname={$config['db']['name']};charset=utf8mb4",
-        $config['db']['user'],
-        $config['db']['pass'],
-        [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]
+    $dsn = sprintf(
+        'mysql:host=%s;dbname=%s;charset=%s',
+        $config['db']['host'],
+        $config['db']['name'],
+        $config['db']['charset']
     );
-} catch (Exception $e) {
-    die('Database connection error');
+    $pdo = new PDO($dsn, $config['db']['user'], $config['db']['pass'], [
+        PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
+        PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
+        PDO::ATTR_EMULATE_PREPARES   => false,
+    ]);
+} catch (PDOException $e) {
+    http_response_code(503);
+    die(json_encode(['success' => false, 'message' => 'Database connection error.']));
 }
+
 return $pdo;