feat(core): register SystemSettings model

app/models/__init__.py

@@ -7,6 +7,7 @@ from app.models.contact import CompanyContact, Contact
 from app.models.currency import Currency
 from app.models.tax import TaxRate
 from app.models.sequence import Sequence
+from app.models.system_settings import SystemSettings
 from app.models.notification import Notification
 from app.models.plugin import Plugin, PluginMigration
 from app.models.role import Role
@@ -31,6 +32,8 @@ __all__ = [
     "Currency",
     "TaxRate",
     "Sequence",
+    "SystemSettings",
+    "SystemSettings",
     "Sequence",
     "TaxRate",
     "Plugin",