Early Access 5.2.1

Fixed: Site-specific update preparation and rollback now target only the selected, valid site; invalid or inaccessible site requests are refused.

Fixed: Bulk update preparation runs only when explicitly requested, and invalid site selections cannot trigger it.

Fixed: Rollback actions now require the appropriate installation permission.

Fixed: Status messages handle missing or error details safely, and displayed text is escaped.

Fixed: The child-update preparation modal now starts with an accurate site total and progress at zero.

Added: Support for Database schema validation.