Migrate from PHP-FPM to Laravel Octane for Docker-native HTTP serving

[aquarion]

Context

Alchemistic is currently deployed as a PHP-FPM container exposing port 9000. The host nginx does fastcgi_pass to that port and handles SSL termination. This means Alchemistic requires a host-nginx vhost to be functional and cannot be routed directly by Traefik.

We're migrating firth's Docker infrastructure to use Traefik as the reverse proxy. Traefik routes HTTP, not FastCGI — so services need to serve HTTP directly to participate.

What needs to change

Switch from PHP-FPM to Laravel Octane (FrankenPHP recommended, or Swoole) so the container serves HTTP on port 8000.

App changes

• composer require laravel/octane
• php artisan octane:install (choose FrankenPHP or Swoole)
• Update Dockerfile to use the FrankenPHP base image or install Swoole extension
• Set OCTANE_SERVER env var accordingly

Infrastructure changes (in autopelago — tracked separately)

Once the image serves HTTP:

• Remove firth_alchemistic_fpm_port variable
• Remove the "Deploy Alchemistic nginx vhost" task block from roles/firth_alchemistic/tasks/main.yml
• Update roles/firth_alchemistic/templates/docker-compose.yml.j2 to add Traefik labels and join the traefik Docker network instead of publishing a FPM port

Precedent

stream-delta already uses Octane on this infrastructure, so the deployment pattern is established.

[aquarion]

Implementation plan tracking this work: aquarion/autopelago#209