Routing

• Define routes via `#[Route]` attributes on controller methods (preferred), or YAML/XML.
• Route parameters: `/users/{id}`. Add `requirements` (regex) and `defaults` to constrain.
• Param converters auto-resolve entities: type-hint `User $user` and Symfony fetches it by id from the URL.
• Generate URLs in PHP with `$urlGenerator->generate('route_name', ['id' => 5])`; in Twig with `{{ path(...) }}`.
• Routes are matched in declaration order — put more specific routes first.
• `bin/console debug:router` lists every route with its path, method, and controller.

#[Route('/users/{id}', name: 'app_user_show', requirements: ['id' => '\d+'], methods: ['GET'])]
public function show(User $user): Response
{
    return $this->render('user/show.html.twig', ['user' => $user]);
}