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/advertisement/tasks.py

@@ -1,47 +1,35 @@
-from venv import create
-from account.tasks import send_email_with_context
+from notifications.tasks import send_email_with_context
 from configuration.models import SiteConfiguration
 
 from celery import shared_task
-from celery.schedules import crontab
 
 from commerce.models import Product
 import datetime
 
+
 @shared_task
 def send_contact_me_email_task(client_email, message_content):
-    context = {
-        "client_email": client_email,
-        "message_content": message_content
-    }
     config_email = SiteConfiguration.get_solo().contact_email
     recipient = config_email if config_email else "brunovontor@gmail.com"
     send_email_with_context(
         recipients=recipient,
         subject="Poptávka z kontaktního formuláře!!!",
         template_path="email/contact_me.html",
-        context=context,
+        context={
+            "client_email": client_email,
+            "message_content": message_content,
+        },
     )
 
 
 @shared_task
 def send_newly_added_items_to_store_email_task_last_week():
     last_week_date = datetime.datetime.now() - datetime.timedelta(days=7)
-
-    """
-    __lte -> Less than or equal
-    __gte -> Greater than or equal
-    __lt -> Less than
-    __gt -> Greater than
-    """
-
     products_of_week = Product.objects.filter(
         include_in_week_summary_email=True,
-        created_at__gte=last_week_date
+        created_at__gte=last_week_date,
     )
-    
     config = SiteConfiguration.get_solo()
-    
     send_email_with_context(
         recipients=config.contact_email,
         subject="Nový produkt přidán do obchodu",
@@ -49,6 +37,5 @@ def send_newly_added_items_to_store_email_task_last_week():
         context={
             "products_of_week": products_of_week,
             "site_currency": config.currency,
-        }
+        },
     )
-