FIXES FRMW-2878 **What** Currently, the `one-to-one` unique constraints does not account for deleted record. This prevents from inserting a new record wth the same fk if another one is deleted. **Caveat** `hasOne` with FK option is meant to be a special case, for example a many to one - one to many without defining the other side of the relation. In that case we don't handle this behaviour and keep it as it is
Promotion Module
The PromotionModule is Medusa’s promotion engine. It offers functionality to discount carts through coupon codes with a given set of rules governing when and how the code should be applied.