- Add API tests for validatePublicURL, testPublicURL, previewInviteURL
- Add UI tests for Public URL validation states and test button
- Add invite URL preview display and debouncing tests
- Increase frontend coverage from 34.85% to 87.7%
Addresses Codecov coverage gaps in PR #450
Closes coverage requirements for beta release
Coverage: 87.7% (1174 tests passing)
