Refactor email templates and add notification tasks

Moved email templates to a unified 'email' directory and added new base, header, and footer templates for emails. Implemented notification tasks in commerce for various order and refund events, and updated Carrier model to trigger notifications on shipping state changes.

backend/commerce/models.py

@@ -10,6 +10,7 @@ from django.core.validators import MaxValueValidator, MinValueValidator
 from weasyprint import HTML
 import os
 
+from backend.commerce.tasks import notify_order_sended
 from configuration.models import ShopConfiguration
 from thirdparty.zasilkovna.models import ZasilkovnaPacket
 from thirdparty.stripe.models import StripeModel
@@ -243,9 +244,16 @@ class Carrier(models.Model):
             self.returning = False
             self.save()
 
+        elif self.shipping_method == self.SHIPPING.STORE:
+            self.state = self.STATE.READY_TO_PICKUP
+            self.save()
+
         else:
             raise ValidationError("Tato metoda dopravy nepodporuje objednání přepravy.")
 
+        
+        notify_order_sended.delay(order=self.orders.first(), user=self.orders.first().user)
+        
         #... další logika pro jiné způsoby dopravy
         #TODO: přidat notifikace uživateli, jak pro zásilkovnu, tak pro vyzvednutí v obchodě!