Make it clearer that custom fields contain data before deleting them

When a workspace is archived, its custom layout is no longer associated with any workspace—it disappears from the custom layouts "Used in" list.

As a result, you may choose to delete custom fields and custom layouts that appear unused, assuming there is no associated data.

A layout still in use by an archived workspace may be deleted. if you decided to reactive that archived workspace, the data may no longer be visible on the record, but this is not a major issue because you can always add back the field to the layout.

However, if you delete the layout any associated custom fields may no longer appears as being linked to a layout. As a result you may delete a custom field that holds data.

When an admin attempts to delete a custom field, provide a warning if that field contains data. Clearly list all workspaces—including archived ones—where data exists for that field. This gives users critical context before deciding to permanently remove a custom field and its associated data.