chrome-release-verify

End-to-end Chrome security backport for an Electron release branch. Given a Chrome Releases blog URL and a branch (e.g. 41-x-y), determines which CVE fixes are missing from the *actual synced source*, writes the cherry-pick patches locally, validates them with `e sync --3` + `lint --patches`, then pushes a single PR. Use when asked to backport a Chrome security release to N-x-y, "is CVE-X already in N-x-y?", or to produce/validate the cherry-pick set for a release branch.