First piece of the generic tabs component: @hive/shared/tabs.css carries
the base .hive-tabbar / .hive-tab / .hive-tab--active styles (lifted from
the logs sub-tab pattern, the most generic of the three tab UIs). Colours
use the semantic theme vars so it inherits theme-swap safety.
Not yet consumed — the createTabStrip JS helper + the per-call-site
migrations (logs, agent window-tabs, dashboard tabbar) follow. Count
pills + the dashboard's responsive overflow menu will layer on top in
the per-page CSS rather than the shared base.