Port the NewDesign/CommentsPanel prototype onto the entire live comment panel,
both card types (agent suggested-edit + human/agent thread) on the new visual,
reusing existing mutations/gates/editor/menu/resolve/anchor-nav (not forked),
zero backend changes. New: agent-edit-card, severity.ts, group-agent-runs.ts.
Delete only the CommentsPanel prototype (TimeWorkedModal/PageHistoryModal belong
to #566/#568 and are deleted by their own PRs).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
