Add a Configuration Option to Disable "Create Subgroup" Button in the UI

Proposal

Currently organizations using API-only automation for governance need to prevent all users, including Owners, from creating subgroups through the UI. Currently, there is no way to disable the UI functionality without also revoking the API permission, which breaks automation scripts. This allows manual, non-compliant subgroup creation to bypass required workflows.

• Introduce a new instance or group-level setting named "Disable subgroup creation from the user interface."

• When enabled, this setting will hide the "Create Subgroup" button and block direct access to the creation page for all users.

• Critically, this setting must not affect the ability to create subgroups via the API for users or tokens with the appropriate permissions.

• This feature would allow administrators to enforce a strict, API-only workflow for subgroup creation, ensuring all subgroups are created with consistent and audited configurations.