fix: security audit remediation — Django settings + payment gateway API

- ALLOWED_HOSTS: wildcard replaced with explicit domain list (#15)
- CORS_ALLOWED_ORIGINS: added app.eventifyplus.com (#16)
- CSRF_TRUSTED_ORIGINS: added app.eventifyplus.com (#18)
- JWT ACCESS_TOKEN_LIFETIME: 1 day reduced to 30 minutes (#19)
- ROTATE_REFRESH_TOKENS enabled
- SECRET_KEY: removed unsafe fallback, crash on missing env var
- Added ActivePaymentGatewayView for dynamic gateway config (#1, #5, #20)
- Added PaymentGatewaySettingsView CRUD for admin panel

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

admin_api/urls.py

@@ -26,7 +26,11 @@ urlpatterns = [
     path('events/stats/', views.EventStatsView.as_view(), name='event-stats'),
     path('events/', views.EventListView.as_view(), name='event-list'),
     path('events/<int:pk>/', views.EventDetailView.as_view(), name='event-detail'),
+    path('events/<int:pk>/update/', views.EventUpdateView.as_view(), name='event-update'),
     path('events/<int:pk>/moderate/', views.EventModerationView.as_view(), name='event-moderate'),
+    path('events/create/', views.EventCreateView.as_view(), name='event-create'),
+    path('events/types/', views.EventTypesView.as_view(), name='event-types'),
+    path('events/<int:pk>/primary-image/', views.EventPrimaryImageView.as_view(), name='event-primary-image'),
     path('financials/metrics/', views.FinancialMetricsView.as_view(), name='financial-metrics'),
     path('financials/transactions/', views.TransactionListView.as_view(), name='transaction-list'),
     path('financials/settlements/', views.SettlementListView.as_view(), name='settlement-list'),
@@ -36,4 +40,9 @@ urlpatterns = [
     path('reviews/', views.ReviewListView.as_view(), name='review-list'),
     path('reviews/<int:pk>/moderate/', views.ReviewModerationView.as_view(), name='review-moderate'),
     path('reviews/<int:pk>/', views.ReviewDeleteView.as_view(), name='review-delete'),
+
+    # Payment gateway settings
+    path('settings/payment-gateway/active/', views.ActivePaymentGatewayView.as_view(), name='active-payment-gateway'),
+    path('settings/payment-gateways/', views.PaymentGatewaySettingsView.as_view(), name='payment-gateways'),
+    path('settings/payment-gateways/<int:pk>/', views.PaymentGatewaySettingsView.as_view(), name='payment-gateway-detail'),
 ]