[dbpolito]

• Replace the AMD64-only Go supervisord binary with distro-packaged Python Supervisor, including foreground logging and process-group shutdown. Supersedes Adding Supervisord Header Config #24.
• Add PHP 8.5 and Debian dev/prod/NGINX variants for PHP 8.4–8.5; retire PHP 8.1. Debian dev images include Node 24 LTS and Yarn.
• Sync NGINX TLS and compression settings with the base image while retaining Octane proxy routing.
• Build and test natively on AMD64 and ARM64 before multi-architecture publishing; verify inherited Dockerize, user switching, and Supervisor lifecycle. Handle base-image update notifications.

ARM64 runtime validation is pending CI. Supervisor lifecycle tests use a PHP server fixture, not a full Laravel installation.