FrankenPHP 1.x reference for modern PHP application server built on Caddy. Use when working with FrankenPHP configuration, worker mode, deployment, performance tuning, Docker setup, Symfony integration, environment variables, or any FrankenPHP-related setup. Triggers on: FrankenPHP, worker mode, Caddy, PHP application server, Symfony Runtime, FrankenPHP deployment, Docker FrankenPHP, Caddyfile, Early Hints, HTTP/3, worker script, FRANKENPHP_CONFIG, Symfony FrankenPHP, production deployment, performance optimization.