Use reported covered lines - W-16286380

[peternhale]

Summary

• use locationsCovered from API v68+ code-coverage responses rather than inferring covered lines
• retain inferred-line behavior for older API versions or responses without locationsCovered
• update generated command schemas and coverage tests

Testing

• yarn test:only -- test/utils/coverage.test.ts
• pre-push hook: lint, compile, test:only, and JSON-schema validation

W-16286380