fix(defaults): remove legacy commerce/products.ts duplicated by products/products.ts

Both exported useProducts, so the generated auto-import manifest carried
the name twice and every server boot warned '[auto-imports] Cannot export
a duplicate name useProducts'. The modular products/ directory (products,
categories, manufacturers, reviews, units) is the canonical home.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: chrisbbreuer