Improve app lane activity popovers

[yvette-carlisle]

Summary

• show current lanes in the Decodex app with compact pills, overflow popovers, and lane activity detail popovers
• add app-style average/delta usage treatment to the operator dashboard
• hydrate API-only operator snapshots from local run state for app display

Validation

• cargo nextest run -p decodex --test operator_status dashboard_renders_app_style_pool_usage_metrics dashboard_renders_active_run_activity_details
• cargo make test-decodex-app-stage