Sprint 3: partner ticket tier CRUD endpoints

- admin_api/views.py: add _serialize_tier(), PartnerMeEventTiersView
  (GET list + POST create with get_or_create TicketMeta),
  PartnerMeEventTierDetailView (PATCH update + DELETE)
- admin_api/urls.py: wire partners/me/events/{event_pk}/tiers/ and
  .../tiers/{tier_pk}/ with named routes partner-me-event-tiers,
  partner-me-event-tier-detail
- Deployed to eventify-backend + eventify-django containers

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

admin_api/urls.py

@@ -30,6 +30,9 @@ urlpatterns = [
     path('partners/me/events/', views.PartnerMeEventsView.as_view(), name='partner-me-events'),
     path('partners/me/events/<int:pk>/', views.PartnerMeEventDetailView.as_view(), name='partner-me-event-detail'),
     path('partners/me/events/<int:pk>/duplicate/', views.PartnerMeEventDuplicateView.as_view(), name='partner-me-event-duplicate'),
+    # Partner-Me: ticket tiers (Sprint 3)
+    path('partners/me/events/<int:event_pk>/tiers/', views.PartnerMeEventTiersView.as_view(), name='partner-me-event-tiers'),
+    path('partners/me/events/<int:event_pk>/tiers/<int:tier_pk>/', views.PartnerMeEventTierDetailView.as_view(), name='partner-me-event-tier-detail'),
     path('users/metrics/', views.UserMetricsView.as_view(), name='user-metrics'),
     path('users/', views.UserListView.as_view(), name='user-list'),
     path('users/<int:pk>/', views.UserDetailView.as_view(), name='user-detail'),