electron-chromium-upgrade

# Electron Chromium Upgrade: Phase One ## Summary Run `e sync --3` repeatedly, fixing patch conflicts as they arise, until it succeeds. Then export patches and commit changes atomically. ## Success Criteria **Linter Requirements**: - Code/patch edits: Title must be exactly `{CL-Number}: {upstream CL original title}` with `Ref: {URL}` in the body. - Metadata-only patch updates (hashes/line numbers): Message must be exactly `chore: update patches` with no body. Phase One is complete when: - `e sync --3` exits with code 0 (no patch failures) - All changes are committed per the commit guidelines Do not stop until these criteria are met. **CRITICAL** Do not delete or skip patches unless 100% certain the patch is no longer needed. Complicated conflicts or hard to resolve issues should be presented to the user after you have exhausted all other options. Do not delete the patch just because you can't solve it. **CRITICAL** Never use `git am --skip` and then manually recreate a patch by making a new commit. This destroys the original patch's authorship, commit message, and position in the series. If `git am --continue` reports "No changes", investigate why — the changes were likely absorbed by a prior conflict resolution's 3-way merge. Present this situation to the user rather than skipping and recreating. ## Context The `roller/chromium/main` branch is created by automation to update Electron's Chromium dependency SHA. No work has been done to handle breaking changes betwee...