### Steps to reproduce

1. Set a session timeout of 5 minutes in [admin settings](https://openproject.local/admin/settings/authentication)

2. Go to a meeting page (/projects/:slug/meetings/:id)

3. Suspend your computer (e.g. close laptop lid) for at least 5 minutes

4. Resume computer and open meetings tab, wait a bit


### What is the buggy behavior?

The browser shows a pop-up to enter username and password (not an OpenProject login form, a browser pop-up).

### What is the expected behavior?

Begin of the insertionNo UI feedback. That might look surprising but there are far too many reasons whyEnd of the insertion Begin of the deletion Weak expectations. Any of:

* Redirecting user to login form (careful: is data-loss possible this way?)

* Showing anEnd of the deletion error Begin of the insertioncould appearEnd of the insertion Begin of the deletion messageEnd of the deletion that Begin of the insertionare only temporary, like network outages or server redeployments. Then it is even annoying that a rather low prioEnd of the insertion Begin of the deletion meeting can't be polled in theEnd of the deletion background Begin of the insertionpolling has a permanent effect on the front-end, e.g. an error flash message. I believe we simply swallow this kind of errors. 

End of the insertion Begin of the deletion

* no UI feedback


End of the deletion ### Technical notes (Root Cause)

The cause of this seems to be, that the frontend code polling `/projects/:slug/meetings/:id/check_for_updates` does not include the `X-Authentication-Scheme: Session` header. All other frontend requests we do, include this header. It is used to guide the server's response in the `WWW-Authenticate` header, which the user interprets to decide whether a login form should be shown or not.

The root cause might be the same as for #64091.

### Screenshots

<img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/605017/content">