[BUG] "Assign to me" assigns alert to wrong user after re-login (userWhoami cached in sessionStorage)

[tcl-ass]

Describe the bug

When a user logs out and logs back in via OIDC/SSO within the same browser tab, the "Assign to me" button on alerts assigns the alert to the previously logged-in user instead of the current one.

This is caused by userWhoami being cached in sessionStorage and not cleared on logout. When a new user logs in, the stale user_id from the previous session is used by the "Assign to me" action.

Relevant code in common.js:

let userWhoami = JSON.parse(sessionStorage.getItem('userWhoami'));

Relevant code in alerts.js:

onclick="updateAlert(${alert.alert_id}, {alert_owner_id: userWhoami.user_id}, true)"

To Reproduce

1. Log in as administrator (local account)
2. Log out
3. Log in as a different user via OIDC/SSO (same browser tab)
4. Go to Alerts
5. Click "Assign to me" on any alert
6. The alert is assigned to administrator instead of the currently logged-in user

Expected behavior

The alert is assigned to the currently authenticated user.

Screenshots

N/A

Desktop (please complete the following information):

• OS: Ubuntu 24.04
• Browser: Firefox 151.0
• Version: IRIS v2.4.27

Smartphone (please complete the following information):

N/A

Additional context

Deployed via Docker using the official docker-compose setup.

The userWhoami object is correctly returned by /user/whoami for the current user, but the cached value in sessionStorage is not invalidated on logout, causing the stale user_id to be used.

Workaround: run in browser console after re-login:

sessionStorage.removeItem('userWhoami');
location.reload();

Suggested fix: clear userWhoami from sessionStorage on logout, or force userWhoamiRequest(true) on every page load regardless of cache.