Add DRF API app and real-time draft management UI

- Created new `api` Django app with serializers, viewsets, and routers
  to expose draft sessions, participants, and movie data.
- Registered `api` app in settings and updated root URL configuration.
- Extended WebSocket consumers with `inform.draft_status` /
  `request.draft_status` to allow fetching current draft state.
- Updated `DraftSession` and related models to support reverse lookups
  for draft picks.
- Enhanced draft state manager to include `draft_order` in summaries.
- Added React WebSocket context provider, connection status component,
  and new admin/participant panels with phase and participant tracking.
- Updated SCSS for participant lists, phase indicators, and status badges.
- Modified Django templates to mount new React roots for admin and
  participant views.
- Updated Webpack dev server config to proxy WebSocket connections.

api/urls.py

@@ -0,0 +1,9 @@
+from rest_framework.routers import DefaultRouter
+from .views import UserViewSet, MovieViewSet, DraftSessionViewSet
+
+router = DefaultRouter()
+router.register(r'users', UserViewSet, basename='user')
+router.register(r'movies', MovieViewSet, basename='movie')
+router.register(r'draft', DraftSessionViewSet, basename='draft')
+
+urlpatterns = router.urls