what:
- adds variant inventory link management endpoints:
```
Link inventory item to variant
POST /products/:id/variants/:vid/inventory-items
Update variant's inventory item link
POST /products/:id/variants/:vid/inventory-items/:iid
Unlink variant's inventory item
DELETE /products/:id/variants/:vid/inventory-items/:iid
```
- a batch endpoint that does the above 3 across variants
```
POST /products/:id/variants/inventory-items
```
* chore: Clean up authentication middlewares
* chore: Rename AuthUser to AuthIdentity
* feat: Define link between user, customer, and auth identity
* feat: Use links for auth, update auth context content
* fix: Adjust user create command with new auth setup
* fix: Make auth login more dynamic, review fixes
* fix: Change test assertions for created by
* feat: initial impl. of Unfulfilled section and create flow
* feat: create fulfillment
* feat: order <> fulfillment link, fulfillment section
* feat: accept order_id when creating fulfillment
* feat: finish create and cancel
* fix: integration test
* refactor: real Order<>Fulfillment link instead readonly, add link step to the workflow
* fix: revert `order_id` definitions
* chore: add changeset
* fix: build
* fix: address comments
* fix: fetch inventory and location levels for fulfilled variant
* fix: loading inventory details
* add isList to order fulfillment link
* fix: duplicate declaration
* fix: type
* refactor: link orders step, fix client
* fix: move translations to the new file
* fix: pass order id in test
---------
Co-authored-by: olivermrbl <oliver@mrbltech.com>
**what**
- Create return workflow partial implementation
- Update some order domain types
- create order fulfillment link
**NOTE**
this PR is partially done but can still be merged as is, it will require some discussions around the flow and some unknowns or uncertainty in regards to some data and some behaviour
