case 4692 - the SuperUser account can not be deleted

UserBiz.ValidateCanDelete refused a delete only when the user had related
records, so SuperUser with none could be deleted and nothing could bring it
back. User 1 is now refused (2004) before any other check. Changelog.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/8.0/ayanova/docs/changelog.md

@@ -31,6 +31,7 @@ IN PROGRESS
 - Server: new [trusted reverse proxies](ops-config-trusted-proxies.md) setting for a reverse proxy that runs on a different computer from the AyaNova server, so AyaNova sees each user's own address.
 - Server: while a report renders, its template no longer holds the User's actual access token or download key; the AyaNova server adds the User's access only to the report's requests to the `ayApiUrl` address. Templates that call the AyaNova API through any other address need to be changed. See [API usage in reports](ay-report-edit.md#api-usage).
 - Server: users with the "Business administration - restricted" role can view [report templates](adm-report-templates.md) but no longer create, edit or import them, as described for that [role](ay-biz-admin-roles.md). Give the full "Business administration" role to users who edit report templates.
+- Server: the SuperUser account can no longer be deleted.
 - Server: the server information page at `/api/v8/` no longer shows license details.
 - Server: business logo uploads must be PNG, JPEG, GIF, WebP or SVG images, and need full rights to global settings. See [business logos](adm-global-logo.md).
 - Server: when a user's password is reset or set by an administrator, or their login is disabled, they are signed out and must sign in again.