✨(backend) add endpoint for frontend's configuration

Inspired by Joanie.

In Frontend context, env variables are only available at build time,
not runtime. This is one of the easiest way to pass frontend dynamic
configurations while running.

This commit only exposes the view already existing.

src/backend/core/urls.py

@@ -5,7 +5,7 @@ from django.urls import include, path
 
 from rest_framework.routers import DefaultRouter
 
-from core.api import viewsets
+from core.api import get_frontend_configuration, viewsets
 from core.authentication.urls import urlpatterns as oidc_urls
 
 # - Main endpoints
@@ -23,6 +23,7 @@ urlpatterns = [
             [
                 *router.urls,
                 *oidc_urls,
+                path("config/", get_frontend_configuration, name="config"),
             ]
         ),
     ),

src/backend/meet/settings.py

@@ -251,6 +251,9 @@ class Base(Configuration):
         "REDOC_DIST": "SIDECAR",
     }
 
+    # Frontend
+    FRONTEND_CONFIGURATION = {}
+
     # Mail
     EMAIL_BACKEND = values.Value("django.core.mail.backends.smtp.EmailBackend")
     EMAIL_HOST = values.Value(None)