test: raise utility coverage above 95 percent

[man4ish]

Summary

• add mocked browser automation coverage for delete and visibility workflows
• cover CLI, retry, error, and edge-case branches across utility scripts
• keep all external browser/API interactions isolated from tests

Verification

• python -m pytest --cov=. --cov-report=term -q
• 49 passed
• 95% coverage (2,195/2,309 statements)