Keep a restored tracked aircraft when Cesium starts or resumes instead of treating it as new navigation

src/cameraHandoff.test.mjs

@@ -114,10 +114,10 @@ test('voice Cockpit entry reaches the camera only through stamping seams', () =>
   assert.doesNotMatch(cockpitTracking, /trackedEntity\s*=/);
   assert.doesNotMatch(cockpitTracking, /flyTo/);
 
-  // Seam 1: any tracker handoff stamps, so the adoption step is covered.
+  // Seam 1: a new tracker handoff stamps; restoring the session does not.
   assert.match(
     ui,
-    /viewer\.trackedEntityChanged\.addEventListener\(\s*\(entity\) => \{\s*if \(entity && !this\._disposed\)\s*this\._stampNavigation\(\{\s*cancelPendingSelection: false,?\s*\}\);/,
+    /viewer\.trackedEntityChanged\.addEventListener\(\s*\(entity\) => \{[\s\S]*?if \(\s*entity &&\s*!this\._disposed &&\s*entity\.gevSelectionOrigin !== 'share-restore'\s*\)\s*this\._stampNavigation\(\{\s*cancelPendingSelection: false,?\s*\}\);/,
     'tracker handoff must stamp',
   );
   // Seam 2 is pinned by "Cockpit takeover invalidates deferred work" above.

src/layers/aircraft/sceneBinding.js

@@ -58,6 +58,7 @@ export function createAircraftSceneBinding({
         parts.snapshots.presentRecords();
         if (flightState._trackedIcao) {
           parts.tracking._trackFlight(flightState._trackedIcao, {
+            origin: 'share-restore',
             resume: true,
             follow: resumeFollow,
           });

src/layers/aircraft/sceneBinding.test.mjs

@@ -0,0 +1,63 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { createAircraftSceneBinding } from './sceneBinding.js';
+import { LayerBindings } from '../../ui/layerBindings.js';
+import { createEngineEvent } from '../../globe/contract.js';
+
+test('resuming an aircraft on Cesium preserves the pending share navigation', (t) => {
+  const previous = globalThis.window;
+  globalThis.window = new EventTarget();
+  t.after(() => {
+    globalThis.window = previous;
+  });
+  const trackedEntityChanged = createEngineEvent();
+  let generation = 1;
+  const shell = new LayerBindings({
+    viewer: { trackedEntityChanged },
+    services: {},
+    operations: {
+      _stampNavigation() {
+        generation++;
+      },
+    },
+  });
+  shell.observeCamera();
+  t.after(() => shell.stop());
+  const renderer = {
+    fleet: { attach() {}, setVisible() {}, restoreOrder() {} },
+    models: { setVisible() {} },
+  };
+  let restored;
+  const binding = createAircraftSceneBinding({
+    id: 'flights',
+    flightState: {
+      initialized: true,
+      _trackedIcao: 'a00000',
+      _preloadModel: {},
+    },
+    services: { renderer: { create: () => renderer } },
+    parts: {
+      snapshots: { presentRecords() {} },
+      tracking: {
+        _trackFlight(id, options) {
+          restored = { id, ...options };
+          trackedEntityChanged.raiseEvent({
+            gevSelectionOrigin: options.origin,
+          });
+        },
+      },
+    },
+  });
+  binding.attachRenderer({});
+  assert.equal(restored.id, 'a00000');
+  assert.equal(restored.resume, true);
+  assert.equal(
+    generation,
+    1,
+    'restored tracking cannot supersede and clear itself',
+  );
+  for (const origin of ['user', 'voice', 'programmatic']) {
+    trackedEntityChanged.raiseEvent({ gevSelectionOrigin: origin });
+  }
+  assert.equal(generation, 4, 'new tracking still takes navigation authority');
+});

src/ui/layerBindings.js

@@ -86,7 +86,13 @@ export class LayerBindings {
     if (this.viewer)
       this._navigationOwnerChangedRemover =
         this.viewer.trackedEntityChanged.addEventListener((entity) => {
-          if (entity && !this._disposed)
+          // Rebinding the session's aircraft is part of the pending share
+          // restoration, not a new navigation that supersedes that restore.
+          if (
+            entity &&
+            !this._disposed &&
+            entity.gevSelectionOrigin !== 'share-restore'
+          )
             this._stampNavigation({ cancelPendingSelection: false });
         });
     // Vessel/installation focus flies without ever assigning a tracked entity,