* feat: sidebar update card (web + macOS) with app-first mac update flow and Sparkle beta track
Squashed from claude/update-notification-display-c6cfb9 after semantic merge
with #104178 (channel-aware CLI installs). See PR #104171 body for details.
* chore(i18n): resync generated inventories after rebase
* chore(i18n): resync locale metadata after rebase