Add scheduler improvements, API endpoints, and month calendar view

Backend:
- Add /api/customers/ endpoint (CustomerViewSet, CustomerSerializer)
- Add /api/services/ endpoint with Service model and migrations
- Add Resource.type field (STAFF, ROOM, EQUIPMENT) with migration
- Fix EventSerializer to return resource_id, customer_id, service_id
- Add date range filtering to EventViewSet (start_date, end_date params)
- Add create_demo_appointments management command
- Set default brand colors in business API

Frontend:
- Add calendar grid view for month mode in OwnerScheduler
- Fix sidebar navigation active link contrast (bg-white/10)
- Add default primaryColor/secondaryColor fallbacks in useBusiness
- Disable WebSocket (backend not implemented) to stop reconnect loop
- Fix Resource.type.toLowerCase() error by adding type to backend

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

smoothschedule/config/urls.py

@@ -10,7 +10,7 @@ from drf_spectacular.views import SpectacularAPIView
 from drf_spectacular.views import SpectacularSwaggerView
 from rest_framework.authtoken.views import obtain_auth_token
 
-from smoothschedule.users.api_views import current_user_view, logout_view
+from smoothschedule.users.api_views import current_user_view, logout_view, send_verification_email, verify_email
 from schedule.api_views import current_business_view
 
 urlpatterns = [
@@ -37,6 +37,8 @@ urlpatterns += [
     path("api/auth-token/", csrf_exempt(obtain_auth_token), name="obtain_auth_token"),
     path("api/auth/me/", current_user_view, name="current_user"),
     path("api/auth/logout/", logout_view, name="logout"),
+    path("api/auth/email/verify/send/", send_verification_email, name="send_verification_email"),
+    path("api/auth/email/verify/", verify_email, name="verify_email"),
     # Business API
     path("api/business/current/", current_business_view, name="current_business"),
     # API Docs