Implement admin fallback redirect

We cannot do this here, since lupus_ce_renderer does not know about the frontend URL. So moving to lupus_decoupled.

so CustomElementsViewSubscriber has that event:

$events[KernelEvents::VIEW][] = ['onKernelView', 100];

where it detects this situation:

// Custom elements requested, but the route does not handle it.
$event->setResponse(new Response('Route does not render into custom elements.', Response::HTTP_NOT_IMPLEMENTED));

in which case we can issue a redirect

ok, when implementing I figured we don't need to know the frontend base URL, so we can just implement this from lupus_ce_renderer, what makes it much easier. so back to it.

it seems to work as a charm. logged out respones for /admin or /node/x/edit are served as normal 403, when logged-in a redirect response is served. as a result local-tasks work like a charme, e.g. you end up e.g. at https://lupus-decoupled.ddev.site/node/1/revisions when clicking on the revisions tab

Tested on a fresh ddev installation. Works as expected!

thanks! also regression tests on a project were fine, so merging.

Automatically closed - issue fixed for 2 weeks with no activity.