fix(health): make +N more and the critical/warning pills interactive

[exzvor]

Summary

Reported via Habr (#34): on the Health dashboard the "+N more" indicator and the header "N critical / N warning" pills looked actionable but did nothing.

• BloatCard's "+N more" is now a button that expands the list to all rows (and collapses again). Tone is still computed over all rows, so expanding never changes the card's severity.
• The critical / warning header pills are now buttons that scroll to the first card of that severity and briefly flash it. Card roots carry data-card-tone (set in CardShell); DOM order matches the dashboard display order, so the first match is the first such card. The scroll respects prefers-reduced-motion. The "ok" pill stays a non-interactive label.

Related issue

Fixes #34

Tests

• BloatCard.test: clicking "+N more" expands to all rows and collapses back. Also stubs window.localStorage (the runner doesn't expose it, which crashed any card test rendering ActionButton via isEasyMode) — fixes two pre-existing failures in that file.
• HealthHeader.test: jumpToTone scrolls to + flashes the first card of the tone; no-op (no throw) when no such card exists.
• Manual smoke — recommended: expand a truncated card; click a severity pill → it scrolls to + flashes the first matching card.

Self-verification

• npm run typecheck / npm run lint clean (incl. design.css)
• npm run test green (health: HealthHeader 10, BloatCard 5, CardShell 7)
• DCO sign-off

Notes for reviewer

Scope: this targets exactly the two reported affordances. BloatCard is the only card that renders a "+N more" today; the other cards silently .slice() without an indicator — adding "+N more" to them is a separate enhancement (left out to keep this focused). The pill jump uses a data-card-tone DOM marker + scrollIntoView (no new store), and a transient .health-card-flash CSS pulse (static ring under reduced-motion). jumpToTone is exported only so it can be unit-tested without seeding the health store.