feat: Add migration script to apply or refresh database schema

backend/scripts/migrate.php

@@ -0,0 +1,46 @@
+<?php
+
+require __DIR__ . '/../vendor/autoload.php';
+
+$envFile = __DIR__ . '/../.env';
+if (file_exists($envFile)) {
+    $lines = file($envFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
+    foreach ($lines as $line) {
+        if (strpos(trim($line), '#') === 0) continue;
+        list($name, $value) = explode('=', $line, 2);
+        putenv(trim($name) . '=' . trim($value));
+    }
+}
+
+$host     = getenv('DB_HOST');
+$port     = getenv('DB_PORT') ?: 3306;
+$dbName   = getenv('DB_DATABASE');
+$user     = getenv('DB_USERNAME');
+$password = getenv('DB_PASSWORD');
+
+try {
+    $pdo = new PDO("mysql:host=$host;port=$port", $user, $password);
+    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+
+    $isFresh = isset($argv[1]) && $argv[1] === 'fresh';
+
+    if ($isFresh) {
+        echo "Dropping database `$dbName`...\n";
+        $pdo->exec("DROP DATABASE IF EXISTS `$dbName`");
+    }
+
+    $pdo->exec("CREATE DATABASE IF NOT EXISTS `$dbName` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci");
+    $pdo->exec("USE `$dbName`");
+
+    $schema = file_get_contents(__DIR__ . '/../database_schema.sql');
+    if (!$schema) {
+        die("Could not read database_schema.sql\n");
+    }
+
+    echo "Executing database_schema.sql...\n";
+    $pdo->exec($schema);
+
+    echo "Database migration completed successfully!\n";
+} catch (PDOException $e) {
+    die("Database Error: " . $e->getMessage() . "\n");
+}