Context

Laravel apps deployed on Octane behave differently from PHP-FPM: the app boots once and stays in memory, so state can leak between requests. Before this, Short Leash could run octane:start only as a background process while .test still went to PHP-FPM, so nothing exercised Octane in development. Octane needs a server binary. Swoole is a PHP extension, and FrankenPHP is a standalone program with PHP built in.

Decision

A site's octane setting (swoole or frankenphp) turns a Laravel site into an app server. Short Leash runs php artisan octane:start --server=<server> --host=127.0.0.1 --port=$PORT and proxies the site to that port, the way it does for command sites.
- FrankenPHP also gets --admin-port=$ADMIN_PORT, a second free port, so several sites can run at once.
- Short Leash adds --watch when the project has chokidar installed.
The site keeps its PHP version and Short Leash's php.ini (PHPRC, PHP_INI_SCAN_DIR) on the server's PATH.
Swoole comes from Short Leash's own PHP builds, so there's nothing extra to download.
FrankenPHP is downloaded from its GitHub releases on first use and checked against the SHA-256 digest GitHub publishes (runtimes::github_tool).
The setting is offered only to Laravel sites that require laravel/octane. Windows offers FrankenPHP only, because Short Leash's Windows PHP builds have no Swoole.

Consequences

Local requests take the same path as production on Octane, including per-request state bugs.
An Octane site is a long-running process. Code changes need --watch (chokidar) or a restart, unlike PHP-FPM, which reads files on every request.
FrankenPHP runs the PHP it was built with, not the site's PHP version, so the version picker matters only for Swoole and the site's CLI processes.
RoadRunner isn't offered: it needs another binary and its own config, and nobody has asked for it.