After live review: the shared account /usage budget read as redundant on
both the Activity and Team tabs. Usage is per-account and can't be split per
member, so one place is enough — it lives only on the Activity tab, next to
the refresh control that fetches it (T-415). Removes the Team-tab account
card, its usage prop wiring, the team.section.usage/team.usage.shared i18n
keys, and the now-obsolete team_tab test. The three-tab card facelift stays.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>