Ports Flutter's UpdateBanner. UpdateBannerController polls
/api/client/version at launch + every 24h, compares the bundled APK
against this build via isVersionNewer, and exposes the available
UpdateInfo (minus in-memory per-version dismissals). The shell banner
nudges "Update Minstrel · {version} available" with Install (reusing
ApkInstaller's download + system-install handoff, routing to the
install-permission settings first when needed) and a dismiss X. Uses an
understated surfaceVariant tone, distinct from the error-colored
VersionTooOldBanner hard gate.
Divergence noted: ApkInstaller exposes no byte progress, so the
downloading state shows an indeterminate bar rather than Flutter's
determinate one.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
bvandeusen
61cf07a3cf