<!-- Add the related story/sub-task/bug number, like Resolves#123, or
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**Related issue:** Resolves#38087
More context:
https://fleetdm.slack.com/archives/C084F4MKYSJ/p1768336339026999 and
https://fleetdm.slack.com/archives/C084F4MKYSJ/p1768512354275959.
## Testing
- [x] Added/updated automated tests
- [ ] Where appropriate, [automated tests simulate multiple hosts and
test for host
isolation](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/reference/patterns-backend.md#unit-testing)
(updates to one hosts's records do not affect another)
- [x] QA'd all new/changed functionality manually
### Okta
NOTE: Okta does not send `DELETE` requests when deleting a user.
Therefore, we decided to perform Fleet users deletion when the
deactivation happens (`PUT` request).
There's an edge case where a `deactivated` user in Okta is `activated`
back again: Okta sends a `POST` request as if a new user was created --
due to this I added an extra check on the `UserHandler Create` function
so that we don't attempt to create a duplicate SCIM user and instead
replace the existing record (basically, the only change should be
`active=0` -> `active=1`).
What I tested:
- [x] Deactivating user in Okta switches `scim_users` record to `active
= 0` and deletes matching `users` records.
- [x] Activating a deactivated user in Okta switches `scim_users` record
to `active = 1`. Note that a `users` record is not created
automatically. For this, there are two alternatives that we'll mention
in the documentation:
1. Manually create a user from the **Users page**.
2. Log in to Fleet using SSO (must have SSO and the **Create user and
sync permissions on login** setting enabled). Note that an activation
email is sent and the user must provide a new password, or an admin in
the Okta dashboard can set up a one-time password and share it with the
user.
https://github.com/user-attachments/assets/5262a581-41f0-4a88-aa73-40768064f8f5
