Drop the feed-row classes (.row, .rowUnread, .body, .meta, .time,
.message, .actions, .empty) — these are replaced by DS DataTable +
EmptyState in follow-up tasks. Keep layout helpers for page shell,
toolbar, filter bar, bulk-action bar, title cell, and DataTable
expanded content. All colors / spacing use DS tokens.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
AlertRow is reused by AllAlertsPage and HistoryPage. Marking a row as read
happens when its link is followed (the detail sub-route will be added in
phase 10 polish). FIRING rows get an amber left border.
