Add weekly new products email and related features

Introduces a weekly summary email for newly added products, including a new email template and Celery periodic task. Adds 'include_in_week_summary_email' to Product and 'newsletter' to CustomUser. Provides an admin endpoint to manually trigger the weekly email, updates Celery Beat schedule, and adds email templates for verification and password reset.

backend/vontor_cz/settings.py

@@ -19,6 +19,7 @@ from django.db import OperationalError, connections
 from datetime import timedelta
 import json
 
+from celery.schedules import crontab
 from dotenv import load_dotenv
 load_dotenv()  # Pouze načte proměnné lokálně, pokud nejsou dostupné
 
@@ -508,6 +509,14 @@ CELERY_TASK_SERIALIZER = os.getenv("CELERY_TASK_SERIALIZER", "json")
 CELERY_RESULT_SERIALIZER = os.getenv("CELERY_RESULT_SERIALIZER", "json")
 CELERY_TIMEZONE = os.getenv("CELERY_TIMEZONE", TIME_ZONE)
 CELERY_BEAT_SCHEDULER = os.getenv("CELERY_BEAT_SCHEDULER")
+
+# Celery Beat Schedule for periodic tasks
+CELERY_BEAT_SCHEDULE = {
+    'send-weekly-new-items-email': {
+        'task': 'advertisement.tasks.send_newly_added_items_to_store_email_task_last_week',
+        'schedule': crontab(hour=9, minute=0, day_of_week=1),  # Every Monday at 9:00 AM
+    },
+}
 #-------------------------------------END CELERY 📅------------------------------------