Replaces the stacked bar + legend with a reclaim-first layout: an amber
hero banner surfaces the total reclaimable bytes and breakdown (unused
images, stopped containers, dangling volumes) with a one-click review &
prune CTA; a three-tile treemap replaces the stacked bar with proportional
areas for Sencho-managed, External, and Reclaimable; and the Volumes tab
gets a two-card landing highlighting the largest volumes by size and
recently changed ones.