V2026 02

[DraTeots]

#v2026-02

1. Update to Angular v21 - allows to move forward
2. Switch from Karma to Vitest. This is partially allowed by Angular21, but it also should remove a lot of dependabot alerts
3. Update of libraries to current versions (e.g. jsroot, three.js, etc)
4. Cleanup unit tests (revision of what is still relevant)
5. Implement Add batch screenshot documentation with configuration guide #84 in the documentation
6. pyrobird - some proactive security measures and fixes

[DraTeots]

#84 is moved here manually due to different directory structure. Lets count it as a merge conflict resolution