Fix : backend intégré en monorepo (suppression git imbriqué)

symfony new crée son propre .git — supprimé pour intégrer
backend/ comme dossier ordinaire dans le monorepo.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/config/routes.yaml

@@ -0,0 +1,11 @@
+# yaml-language-server: $schema=../vendor/symfony/routing/Loader/schema/routing.schema.json
+
+# This file is the entry point to configure the routes of your app.
+# Methods with the #[Route] attribute are automatically imported.
+# See also https://symfony.com/doc/current/routing.html
+
+# To list all registered routes, run the following command:
+#   bin/console debug:router
+
+controllers:
+    resource: routing.controllers