Add wallet balance to User model and implement Atoll/Island management

- Added `wallet_balance` field to the User model.
- Updated UserAdmin to include `wallet_balance` in the admin interface.
- Created serializers and views for Atoll and Island management.
- Implemented endpoints for listing, creating, and updating Atolls and Islands.
- Enhanced payment processing with UUIDs for Payment and Topup models.
- Added migration files for new fields and constraints.
- Improved error handling and validation in various views.
- Updated email templates for better responsiveness and SEO.

api/signals.py

@@ -7,17 +7,23 @@ from django.db.models.signals import post_save
 from api.models import User
 from django.contrib.auth.models import Permission
 
+
 @receiver(post_save, sender=User)
 def assign_device_permissions(sender, instance, created, **kwargs):
     if created:
         # Assign all permissions for devices and read permission for atoll and island
-        device_permissions = Permission.objects.filter(content_type__model='device')
-        atoll_read_permission = Permission.objects.get(codename='view_atoll')
-        island_read_permission = Permission.objects.get(codename='view_island')
+        device_permissions = Permission.objects.filter(content_type__model="device")
+        atoll_read_permission = Permission.objects.get(codename="view_atoll")
+        island_read_permission = Permission.objects.get(codename="view_island")
+        payment_permissions = Permission.objects.filter(
+            content_type__model="payment"
+        ).exclude(codename="delete_payment")
 
         for permission in device_permissions:
             instance.user_permissions.add(permission)
         instance.user_permissions.add(atoll_read_permission, island_read_permission)
+        for permission in payment_permissions:
+            instance.user_permissions.add(permission)
 
 
 @receiver(reset_password_token_created)