feat: scaffold Django multi-tenant project with 5 of 9 apps

Phase 1 scaffolding: config/, core/, base models, AES-256-GCM phone encryption, enums mirror

apps.tenant: Tenant + Domain (django-tenants)

apps.org: 11 models (OrgUnit hierarchy, Staff, audit logs)

apps.account: 4 models (UserAccount as AUTH_USER_MODEL, login/password tracking)

apps.permission: 7 models (RBAC + overrides + datascope + append-only changelog)

apps.region: 5 models (District, BusinessArea, MetroLine, MetroStation, School)

All migrations generated, manage.py check passes

apps/tenant/models.py

@@ -0,0 +1,13 @@
+from django.db import models
+from django_tenants.models import DomainMixin, TenantMixin
+
+
+class Tenant(TenantMixin):
+    name = models.CharField(max_length=255)
+    created_on = models.DateField(auto_now_add=True)
+
+    auto_create_schema = True
+
+
+class Domain(DomainMixin):
+    pass