## Summary of the Pull Request
Basic UI Tests for Screen Ruler module
## PR Checklist
- [ ] Closes: https://github.com/microsoft/PowerToys/issues/40670
- [x] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [x] **Tests:** Added/updated and all pass
- [x] **Dev docs:** Added/updated
## Detailed Description of the Pull Request / Additional comments
Covered test cases you can find in this issue:
https://github.com/microsoft/PowerToys/issues/40670