more fixes

backend/igny8_core/business/billing/admin.py

@@ -6,6 +6,7 @@ with full workflow functionality. This file contains legacy/minimal registration
 """
 from django.contrib import admin
 from django.utils.html import format_html
+from unfold.admin import ModelAdmin
 from igny8_core.admin.base import AccountAdminMixin
 from .models import (
     CreditCostConfig,
@@ -49,7 +50,7 @@ from .models import (
 # or have minimal implementations that don't conflict
 
 @admin.register(AccountPaymentMethod)
-class AccountPaymentMethodAdmin(admin.ModelAdmin):
+class AccountPaymentMethodAdmin(ModelAdmin):
     list_display = [
         'display_name',
         'type',