move / check into separat feature ("root")

Signed-off-by: Peter Siegmund <developer@mars3142.org>

server/cinema/lib/feature/poster/poster.service.dart

@@ -10,12 +10,12 @@ part 'poster.service.g.dart';
 @injectable
 class PosterService {
   @Route.get('/')
-  Future<Response> listPosters(Request request) async {
+  Future<Response> getRoot(Request request) async {
     return Response.ok('deprecated poster endpoint. use POST /poster instead');
   }
 
   @Route.post('/')
-  Future<Response> createPoster(Request request) async {
+  Future<Response> postRoot(Request request) async {
     final payload = await request.readAsString();
     final body = jsonDecode(payload);
     final params = posterSchema.safeParse(body);
@@ -32,6 +32,5 @@ class PosterService {
     return Response.ok(jsonEncode(params.data), headers: {'Content-Type': 'application/json'});
   }
 
-  // Create router using the generate function defined in 'poster.g.dart'.
   Router get router => _$PosterServiceRouter(this);
 }