Introduce notifications app and integrate emails

Add a new notifications app (models, serializers, views, admin, tasks, consumers, routing, urls, tests) with Notification.notify for in-app websocket pushes and optional email delivery. Centralize email sending in notifications.tasks.send_email_with_context and re-export it from account.tasks for compatibility. Update account and commerce and advertisement tasks to use Notification.notify/_notify_order and the new email helper; adjust order/notification tasks to consolidate logic. Wire notifications into ASGI routing, settings and URL conf. Misc: handle OSError when importing weasyprint, add tmp/ to .gitignore, add local .claude PowerShell checks, add social.blog skeleton, and remove legacy ews-component test files.

backend/vontor_cz/asgi.py

@@ -18,9 +18,10 @@ django_asgi_app = get_asgi_application()
 from channels.routing import ProtocolTypeRouter, URLRouter
 from social.chat.routing import websocket_urlpatterns as social_ws
 from thirdparty.downloader.routing import websocket_urlpatterns as downloader_ws
+from notifications.routing import websocket_urlpatterns as notifications_ws
 from vontor_cz.middleware import JWTAuthMiddleware
 
-websocket_urlpatterns = downloader_ws + social_ws
+websocket_urlpatterns = downloader_ws + social_ws + notifications_ws
 
 application = ProtocolTypeRouter({
     "http": django_asgi_app,

backend/vontor_cz/settings.py

@@ -348,6 +348,7 @@ MY_CREATED_APPS = [
     'social.posts',
 	
     'advertisement',
+    'notifications',
 
     'thirdparty.downloader',
     'thirdparty.stripe',  # register Stripe app so its models are recognized

backend/vontor_cz/urls.py

@@ -43,6 +43,7 @@ urlpatterns = [
     path('api/configuration/', include('configuration.urls')),
     path('api/advertisement/', include('advertisement.urls')),
 
+    path('api/notifications/', include('notifications.urls')),
     path('api/social/hubs/', include('social.hubs.urls')),
     path('api/social/posts/', include('social.posts.urls')),
     path('api/social/', include('social.chat.urls')),