**What**
- remove cascade delete of inventory items on product delete
- implement inventory deletion in product/variant delete workflows with checks:
- product/variant cannot be deleted if there are reservations associated with their inventory items
- inventory item will be cascade deleted if it's not used by other variants (that are not being deleted in the current flow)
---
FIXES CC-581 CC-582
what:
- when an empty array is passed to the workflow, it attempts to delete all inventory locations. This PR adds a conditional to prevent it from happening.
RESOLVES CC-477
Fixes https://github.com/medusajs/medusa/issues/9154
what:
- santizes inputs to prevent reserved_quantity from being updated directly
- inventory items create api can create location levels
- add validation to update quantity of reservation items
- general cleanup
RESOLVES CORE-2254
