Create address

Create and persist a shipping or billing address for the authenticated user.

Use this endpoint when the user confirms a new address in checkout or account settings.

Common ways to call this endpoint:

1. Assisted flow: find address -> retrieve details -> create saved address.
2. Manual flow: user enters address fields directly, then create.

Request guidance:

• type must be shipping or billing.
• country should be an ISO 3166-1 alpha-2 country code (for example, GB).
• Set loqateId and isValidated when the address came from the lookup endpoints.
• Set isPrimary to true when this should become the default address for that type.

Behavior notes:

• Returns 201 with the newly saved address record.
• A user can store up to 10 addresses in total; additional creates return 400.
• If isPrimary is true, existing primary addresses of the same type are replaced.
• After creation, call GET /user/addresses to refresh the full address list in UI.