wip(mobile): checkpoint engine and experience round three in progress

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01VVYRAqiQj9Y1V9ZfG1RcDH

mobile/ui/stubSituations.js

@@ -348,6 +348,35 @@ export function buildStubSituations(now) {
       severity: 1,
       age: 0,
     }),
+    S({
+      id: 'circling-midtown',
+      kind: 'circling',
+      family: 'sky',
+      band: 'sky',
+      archetype: 'track',
+      severity: 4,
+      live: false,
+      title: '3 helicopters circled Midtown Manhattan',
+      subtitle: 'Detected from orbiting tracks · replay the Moment',
+      place: 'Empire State Building, New York',
+      lon: -73.98566,
+      lat: 40.74844,
+      span: 0.05,
+      th: 520,
+      height: 6000,
+      layers: ['sky.helicopters', 'sky.commercial-flights'],
+      metrics: [
+        { label: 'Rotorcraft', value: 3, unit: '' },
+        { label: 'Orbit radius', value: '450–650', unit: 'm' },
+        { label: 'Altitude', value: '1,050–1,450', unit: 'ft' },
+      ],
+      headline: { value: 3, unit: 'helis', label: 'circling one point' },
+      telemetry: 'SKY · 3 ROTORCRAFT · R 450–650 M · 1,050–1,450 FT',
+      momentId: 'empire-state',
+      illustrative: true,
+      track: { headingDeg: 0, circuit: true },
+      age: 76,
+    }),
     S({
       id: 'novosel',
       kind: 'helicopters',