Use ory.sh SSO for third parties app

In https://github.com/kiwix/overview/issues/90#issuecomment-3404879023, we've decided to focus ory.sh on our own apps first, and then on third-parties when feasible.

No effort has been done so far on how to integrate these third-parties. There is especially a need to provide authorization while ory.sh project has only focused on authentication so far (https://github.com/kiwix/overview/issues/132 is still pending).

We now have a real use case where we would really like to integration SSO: https://github.com/kiwix/operations/issues/749 ; probably the right time to move things forward