fix: Add MYSQL_PWD environment variable for database healthcheck

- Fixes MariaDB container healthcheck authentication failures
- Adds MYSQL_PWD environment variable so healthcheck script can authenticate
- Resolves 'Access denied for user root@localhost' warnings
- Ensures database container properly reports healthy status

docker-compose.yml

@@ -21,6 +21,8 @@ services:
       MYSQL_PASSWORD: ${DB_PASSWORD}
       MYSQL_INNODB_BUFFER_POOL_SIZE: ${MYSQL_BUFFER_POOL}
       MYSQL_MAX_CONNECTIONS: ${MYSQL_MAX_CONNECTIONS}
+      # Healthcheck authentication
+      MYSQL_PWD: ${MYSQL_ROOT_PASSWORD}
     
     ports:
       - "${DB_PORT}:3306"