feat: add the booking domain layer

.env

@@ -30,10 +30,10 @@ DEFAULT_URI=http://localhost
 # Format described at https://www.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/configuration.html#connecting-using-a-url
 # IMPORTANT: You MUST configure your server version, either here or in config/packages/doctrine.yaml
 #
-# DATABASE_URL="sqlite:///%kernel.project_dir%/var/data_%kernel.environment%.db"
-# DATABASE_URL="mysql://app:[email protected]:3306/app?serverVersion=8.0.32&charset=utf8mb4"
-# DATABASE_URL="mysql://app:[email protected]:3306/app?serverVersion=10.11.2-MariaDB&charset=utf8mb4"
-DATABASE_URL="postgresql://app:[email protected]:5432/app?serverVersion=16&charset=utf8"
+# MariaDB 11.x, as provided by DDEV. The mysql:// scheme is just DBAL's pdo_mysql alias --
+# serverVersion is what selects MariaDBPlatform over MySQLPlatform, so keep it in sync with
+# the container. DDEV writes the same value into the gitignored .env.local.
+DATABASE_URL="mysql://db:db@db:3306/db?charset=utf8mb4&serverVersion=11.8.0-mariadb"
 ###< doctrine/doctrine-bundle ###
 
 ###> symfony/messenger ###