Allow creating folders (SchemaItemGroup) directly in the model tree,
e.g. a “Lookups” folder under “Data Structures”.
Add a “New Folder” action to provider and folder context menus
Add POST /Model/CreateGroup endpoint creating a group under the node
Validate the folder name in the dialog (empty, invalid path characters, duplicates) with translatable messages; keep the same checks on the backend as a defensive net
Reload, expand and highlight the newly created folder in the tree