fix: fix all dev static/media serving issues

- Remove WhiteNoise from MIDDLEWARE in development: it intercepts /static/
  requests and serves from STATIC_ROOT, which is empty without collectstatic.
  Django's runserver serves static files natively with DEBUG=True.
- Switch to StaticFilesStorage in dev: no manifest required.
- Add media URL pattern in DEBUG mode: runserver does not serve MEDIA_ROOT
  automatically, so uploaded images were 404ing in local dev.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

config/urls.py

@@ -1,3 +1,5 @@
+from django.conf import settings
+from django.conf.urls.static import static
 from django.contrib import admin
 from django.urls import include, path
 from django.views.generic import RedirectView
@@ -21,3 +23,6 @@ urlpatterns = [
     path("admin/", RedirectView.as_view(url="/cms/", permanent=False)),
     path("", include(wagtail_urls)),
 ]
+
+if settings.DEBUG:
+    urlpatterns += static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)