[Task] The plugin's routes need Sylius's path parameter and symfony/yaml, which it does not require

[gplanchat]

Parent Epic: #311

Refs #496, #519.

Both issues came up while checking #519's non-Sylius case with a throwaway micro-kernel (FrameworkBundle, TwigBundle and DurablePlugin, no Sylius, on the root's Symfony 8 vendor). Neither is a Twig error, and neither was introduced by #519. In both cases the request never reaches the controller, so #519's 404 guard only covers a kernel that defines sylius_admin.path_name but has no Sylius admin layout.

1. The route path needs a Sylius parameter

Since #496, src/DurablePlugin/config/routes.yaml declares path: /%sylius_admin.path_name%/durable/dashboard. Only Sylius's AdminBundle defines that parameter (AdminBundle/Resources/config/app/config.yml:9). Without Sylius, requesting the route throws:

Symfony\Component\DependencyInjection\Exception\ParameterNotFoundException:
You have requested a non-existent parameter "sylius_admin.path_name".

2. The routes are YAML, and the plugin does not require symfony/yaml

gplanchat/durable-plugin's composer.json requires symfony/routing but not symfony/yaml. An application without symfony/yaml that imports @DurablePlugin/config/routes.yaml fails on every request:

Error: Class "Symfony\Component\Yaml\Parser" not found

Every Sylius application has symfony/yaml, so today only a non-Sylius application hits this.

Options

• (2), with no manifest change: ship the route as config/routes.php in the closure format (return static function (RoutingConfigurator $routes): void { … };).
  • Symfony\Component\Routing\Loader\PhpFileLoader is part of symfony/routing, which the plugin already requires. It only delegates to the YAML loader when the file returns an array, so the closure format needs no YAML.
  • This is a BC change for shops, which import @DurablePlugin/config/routes.yaml. The options are to keep a routes.yaml alongside for one release, or to document the new import in UPGRADE.md.
• (2), with a manifest change: add symfony/yaml to the plugin's require. composer.json is a hard limit, so a human must decide.
• (1): either keep the Sylius parameter and state that the plugin's routes need the Sylius admin, or give the plugin a fallback when the parameter is absent (for example a prefix of its own, set in prepend() only when the parameter is not defined). Take care with ordering: Sylius defines the parameter in its app config.

Done when

• A kernel without Sylius (and without symfony/yaml) that imports the plugin's routes boots, and the dashboard route answers the feat(plugin): the Sylius admin hooks compose the dashboard; a previous-page link (#383 slice A, #256) #519 404 instead of an exception. A kernel test proves it.
• A Sylius shop still reaches the dashboard under its admin prefix, as the Sylius bench job shows.

[gplanchat]

Decision (the user, 2026-09-26): point 2 is settled by adding symfony/yaml to the plugin's require. The routes stay YAML, no BC for shops. That changes the first Done-when box: the kernel without Sylius has symfony/yaml (it comes with the plugin now).

Point 1 (the sylius_admin.path_name parameter) takes the fallback: a prefix of the plugin's own when the parameter is not defined, with care for ordering, since Sylius defines it in its app config. The Done-when's kernel test (boots without Sylius, the dashboard route answers #519's 404) and the Sylius bench job stay the proof.

Starts after #555 (route split) is on main. Assigned to emma, reviewed by jack. bob also adds sylius/grid-bundle to the same manifest for #383 slice B: whichever lands second merges main.