POST /sync starts the full synchronization in the background (202, or 409 when one is already running). Entities are synced in dependency order: brands, categories, suppliers, products (with versions and stocks), customers. Each row is synced independently so that a failure is logged without stopping the rest. Replaces the default AppService.
Generate the Prisma client on postinstall. Jest now transpiles the ESM-only @nestjs/config and maps the .js imports of the generated Prisma client, in both the unit and e2e configurations.