Changelog

3.1.0

Added an Admin-managed product model catalog.
Added create, rename, archive, reactivate, and safe-delete model actions.
Added available and sold usage counts for every model.
Preserved archived model names throughout inventory, sales, and customer history.
Added automatic pre-migration database backups for upgrades from the fixed model list.
Added responsive, light, and dark theme styling for model management.
Added API and migration regression coverage.

Corrected fresh-install initialization so inventory, sales, and customers begin empty.