fix(street-level): a delayed photo never overrides newer navigation; retry failed mesh refreshes

- A photo takes a deferred navigation ticket when it starts opening
  (begin/reassert, the application's _beginDeferredNavigation and
  _reassertNavigationHandoff) and frames only if that ticket still owns
  the camera once loaded, so a slow photo no longer flies the camera back
  over newer navigation or clears newer aircraft tracking.
- A failed mesh refresh keeps the last good sample and the distance it was
  taken from, and is retried after the miss cooldown, instead of recording
  the failed distance and never refreshing again.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/layers/streetLevel/cameraFollow.test.mjs

@@ -79,7 +79,7 @@ function setup({ sampled, dem = null, globe = null, altitude = 149 }) {
 
 test('framing a photo ignores a sample kilometres underground and uses bare earth', () => {
   const { follow, flights } = setup({ sampled: -14_886, dem: 117 });
-  follow.lookAtPosition();
+  follow.lookAtPosition(follow.beginFraming());
   assert.equal(flights.length, 1);
   const centre = heightOf(flights[0].sphere.center);
   assert.ok(
@@ -90,7 +90,7 @@ test('framing a photo ignores a sample kilometres underground and uses bare eart
 
 test('a plausible mesh sample near bare earth wins (a street, or a modest roof)', () => {
   const { follow, flights } = setup({ sampled: 121, dem: 117 });
-  follow.lookAtPosition();
+  follow.lookAtPosition(follow.beginFraming());
   assert.ok(Math.abs(heightOf(flights[0].sphere.center) - 123) < 0.01);
 });
 
@@ -101,7 +101,7 @@ test('without bare earth an absurd sample falls back to the image altitude, neve
     globe: undefined,
     altitude: 149,
   });
-  follow.lookAtPosition();
+  follow.lookAtPosition(follow.beginFraming());
   assert.ok(Math.abs(heightOf(flights[0].sphere.center) - 151) < 0.01);
 });
 
@@ -119,15 +119,15 @@ test('following stands the camera at eye height above the checked ground', () =>
 test('cancelFraming stops the framing flight while it is still ours', () => {
   const { follow, state } = setup({ sampled: 121, dem: 117 });
   const { camera } = state.viewer;
-  follow.lookAtPosition();
+  follow.lookAtPosition(follow.beginFraming());
   follow.cancelFraming();
   assert.equal(camera.cancelled, 1, 'the flight toward the closed photo stops');
   follow.cancelFraming();
   assert.equal(camera.cancelled, 1, 'and only once');
 
   // Re-framing (the next photo) supersedes the first flight, not the claim.
-  follow.lookAtPosition();
-  follow.lookAtPosition();
+  follow.lookAtPosition(follow.beginFraming());
+  follow.lookAtPosition(follow.beginFraming());
   follow.cancelFraming();
   assert.equal(camera.cancelled, 2);
 });
@@ -135,12 +135,12 @@ test('cancelFraming stops the framing flight while it is still ours', () => {
 test('cancelFraming leaves a landed flight and a newer navigation flight alone', () => {
   const { follow, state, flights } = setup({ sampled: 121, dem: 117 });
   const { camera } = state.viewer;
-  follow.lookAtPosition();
+  follow.lookAtPosition(follow.beginFraming());
   camera.land();
   follow.cancelFraming();
   assert.equal(camera.cancelled, 0, 'landed: nothing to stop');
 
-  follow.lookAtPosition();
+  follow.lookAtPosition(follow.beginFraming());
   // A search result flies the globe elsewhere; Cesium cancels ours first.
   camera.flyToBoundingSphere(null, {});
   assert.equal(flights.length, 3);
@@ -151,7 +151,7 @@ test('cancelFraming leaves a landed flight and a newer navigation flight alone',
 test('turning FOLLOW on stops the framing flight so it cannot fight the follow view', () => {
   const { follow, state, views } = setup({ sampled: 121, dem: 117 });
   const { camera } = state.viewer;
-  follow.lookAtPosition();
+  follow.lookAtPosition(follow.beginFraming());
   follow.setFollow(true);
   assert.equal(camera.cancelled, 1, 'the framing tween stops');
   assert.equal(views.length, 1, 'and the camera stands at the photo');
@@ -163,43 +163,73 @@ test('turning FOLLOW on stops the framing flight so it cannot fight the follow v
  */
 function navigationFor(state, { refuse = false } = {}) {
   const listeners = new Set();
+  let generation = 0;
+  const stamp = () => {
+    generation++;
+    for (const listener of listeners) listener({ generation });
+    return generation;
+  };
   const nav = {
     runs: [],
+    begins: [],
     run(noun, move) {
       nav.runs.push(noun);
       if (refuse) return false;
-      for (const listener of listeners)
-        listener({ generation: nav.runs.length });
+      const current = stamp();
       state.viewer.trackedEntity = undefined;
-      return move(nav.runs.length);
+      return move(current);
+    },
+    /** Deferred: stamp now, release only on a successful reassert. */
+    begin(noun) {
+      nav.begins.push(noun);
+      return refuse ? false : stamp();
+    },
+    reassert(ticket) {
+      if (ticket !== generation) return false;
+      state.viewer.trackedEntity = undefined;
+      return true;
     },
     subscribeHandoff(listener) {
       listeners.add(listener);
       return () => listeners.delete(listener);
     },
-    handOff() {
-      for (const listener of listeners) listener({ generation: -1 });
-    },
+    /** Another feature takes the camera. */
+    handOff: () => stamp(),
     listeners,
   };
   return nav;
 }
 
-test('framing a photo claims the camera through the application, releasing tracking', () => {
+test('a photo claims the camera when it starts opening and frames once loaded, releasing tracking', () => {
   const { follow, state, flights } = setup({ sampled: 160 });
   state.viewer.trackedEntity = { id: 'aircraft' };
   const nav = navigationFor(state);
   follow.attachNavigation(nav);
-  follow.lookAtPosition();
-  assert.deepEqual(nav.runs, ['photo']);
+  const ticket = follow.beginFraming();
+  assert.deepEqual(nav.begins, ['photo']);
+  assert.ok(state.viewer.trackedEntity, 'nothing is released while it loads');
+  follow.lookAtPosition(ticket);
   assert.equal(state.viewer.trackedEntity, undefined);
   assert.equal(flights.length, 1);
 });
 
+test('a photo that finishes loading after newer navigation does not frame', () => {
+  const { follow, state, flights } = setup({ sampled: 160 });
+  const nav = navigationFor(state);
+  follow.attachNavigation(nav);
+  const ticket = follow.beginFraming();
+  // The user flies to Sacramento, and then tracks an aircraft, while it loads.
+  nav.handOff();
+  state.viewer.trackedEntity = { id: 'aircraft' };
+  follow.lookAtPosition(ticket);
+  assert.equal(flights.length, 0, 'no flight back to the photo');
+  assert.deepEqual(state.viewer.trackedEntity, { id: 'aircraft' });
+});
+
 test('a refused claim (cockpit) neither frames the photo nor turns FOLLOW on', () => {
   const { follow, state, flights, views } = setup({ sampled: 160 });
   follow.attachNavigation(navigationFor(state, { refuse: true }));
-  follow.lookAtPosition();
+  follow.lookAtPosition(follow.beginFraming());
   follow.setFollow(true);
   assert.equal(flights.length, 0);
   assert.equal(views.length, 0);