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/account/tasks.py

@@ -1,121 +1,80 @@
 from celery import shared_task
 from celery.utils.log import get_task_logger
-from django.core.mail import send_mail
 from django.conf import settings
 from django.utils.http import urlsafe_base64_encode
 from django.utils.encoding import force_bytes
-from django.template.loader import render_to_string
 from .tokens import *
 from .models import CustomUser
 
+# Re-exported so existing imports from account.tasks still work
+from notifications.tasks import send_email_with_context  # noqa: F401
+
 logger = get_task_logger(__name__)
 
-def send_email_with_context(recipients, subject, template_path=None, context=None, message: str | None = None):
-    """
-    Send emails rendering a single HTML template.
-    - `template_name` is a simple base name without extension, e.g. "email/test".
-    - Renders only HTML (".html"), no ".txt" support.
-    - Converts `user` in context to a plain dict to avoid passing models to templates.
-    """
-    if isinstance(recipients, str):
-        recipients = [recipients]
 
-    html_message = None
-    if template_path:
-        ctx = dict(context or {})
-        # Render base layout and include the provided template as the main content.
-        # The included template receives the same context as the base.
-        html_message = render_to_string(
-            "email/components/base.html",
-            {"content_template": template_path, **ctx},
-        )
-
-    try:
-        send_mail(
-            subject=subject,
-            message=message or "",
-            from_email=None,
-            recipient_list=recipients,
-            fail_silently=False,
-            html_message=html_message,
-        )
-        if settings.EMAIL_BACKEND == 'django.core.mail.backends.console.EmailBackend' and message:
-            logger.debug(f"\nEMAIL OBSAH:\n{message}\nKONEC OBSAHU")
-        return True
-    except Exception as e:
-        logger.error(f"E-mail se neodeslal: {e}")
-        return False
-    
-
-#----------------------------------------------------------------------------------------------------
-
-# This function sends an email to the user for email verification after registration.
 @shared_task
 def send_email_verification_task(user_id):
+    from notifications.models import Notification
     try:
         user = CustomUser.objects.get(pk=user_id)
     except CustomUser.DoesNotExist:
-        logger.info(f"Task send_email_verification has failed. Invalid User ID was sent.")
-        return 0
-    
+        logger.info("send_email_verification_task: invalid user_id %s", user_id)
+        return
+
     uid = urlsafe_base64_encode(force_bytes(user.pk))
-    # {changed} generate and store a per-user token
     token = user.generate_email_verification_token()
     verify_url = f"{settings.FRONTEND_URL}/email-verification/?uidb64={uid}&token={token}"
 
-    context = {
-        "user": user,
-        "action_url": verify_url,
-        "frontend_url": settings.FRONTEND_URL,
-        "cta_label": "Ověřit e‑mail",
-    }
-
-    send_email_with_context(
-        recipients=user.email,
-        subject="Ověření e‑mailu",
+    Notification.notify(
+        user=user,
+        title="Ověření e‑mailu",
+        text="Prosím ověřte svou e-mailovou adresu kliknutím na odkaz v e-mailu.",
+        action_url=verify_url,
         template_path="email/email_verification.html",
-        context=context,
+        email_context={
+            "action_url": verify_url,
+            "frontend_url": settings.FRONTEND_URL,
+            "cta_label": "Ověřit e‑mail",
+        },
     )
 
 
-
 @shared_task
 def send_email_test_task(email):
-    context = {
-        "action_url": settings.FRONTEND_URL,
-        "frontend_url": settings.FRONTEND_URL,
-        "cta_label": "Otevřít aplikaci",
-    }
     send_email_with_context(
         recipients=email,
         subject="Testovací e‑mail",
         template_path="email/test.html",
-        context=context,
+        context={
+            "action_url": settings.FRONTEND_URL,
+            "frontend_url": settings.FRONTEND_URL,
+            "cta_label": "Otevřít aplikaci",
+        },
     )
 
 
 @shared_task
 def send_password_reset_email_task(user_id):
+    from notifications.models import Notification
     try:
         user = CustomUser.objects.get(pk=user_id)
     except CustomUser.DoesNotExist:
-        logger.info(f"Task send_password_reset_email has failed. Invalid User ID was sent.")
-        return 0
-    
+        logger.info("send_password_reset_email_task: invalid user_id %s", user_id)
+        return
+
     uid = urlsafe_base64_encode(force_bytes(user.pk))
     token = password_reset_token.make_token(user)
     reset_url = f"{settings.FRONTEND_URL}/reset-password/{uid}/{token}"
 
-    context = {
-        "user": user,
-        "action_url": reset_url,
-        "frontend_url": settings.FRONTEND_URL,
-        "cta_label": "Obnovit heslo",
-    }
-
-    send_email_with_context(
-        recipients=user.email,
-        subject="Obnova hesla",
+    Notification.notify(
+        user=user,
+        title="Obnova hesla",
+        text="Byl vyžádán reset vašeho hesla. Klikněte na odkaz pro nastavení nového hesla.",
+        action_url=reset_url,
         template_path="email/password_reset.html",
-        context=context,
-    )
+        email_context={
+            "action_url": reset_url,
+            "frontend_url": settings.FRONTEND_URL,
+            "cta_label": "Obnovit heslo",
+        },
+    )