README: settings file, --config, the new tab. ARCHITECTURE.md and
CLAUDE.md: prepare() hook, app command-line options, app code layout,
WebEngine notes, the moc raw-string pitfall. THIRD_PARTY_NOTICES: Qt
WebEngine. Ship config.example.json; the package README explains the
set-up. PROGRESS.md and DESIGN.md: phase 3 results and deviations.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
