Adds an About card to Settings that shows the installed version
(version+build from PackageInfo), the latest known version from
clientUpdateProvider, and a "Check for updates" button that
invalidates the provider to force a fresh poll. When an update is
available, surfaces an Install CTA that reuses the same installer
flow as the top banner.
The existing banner (shouldShowUpdateBannerProvider) is unaffected
— it gates on per-version dismissal, while the About section
always reflects the current provider state regardless of dismissal.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
