Guards against the Akka singleton Ask hang regression: asserts all nine KPI
tiles on /monitoring/health resolve to numeric values and never show the
em-dash degrade placeholder (—). Covers Notification Outbox, Audit, and
Site Call tile groups. Selector disambiguation: Outbox tiles are div.card,
Site Call tiles are button.card — prevents strict-mode collisions on the
shared "Stuck" and "Parked" labels.
Joseph Doherty