Integrate @bgotink/playwright-coverage for E2E test coverage tracking:
Install @bgotink/playwright-coverage package
Update playwright.config.js with coverage reporter
Update test file imports to use coverage-enabled test function
Add e2e-tests.yml coverage artifact upload and merge job
Create codecov.yml with e2e flag configuration
Add E2E coverage skill and VS Code task
Coverage outputs: HTML, LCOV, JSON to coverage/e2e/
CI uploads merged coverage to Codecov with 'e2e' flag
Enables unified coverage view across unit and E2E tests
