fix(camera): orbit on drags from the stars above 1,000 km

Below Cesium's trackball height (7,500 km by default) a drag that starts
on the stars turns the camera in place, whatever enableLook says, which
was the drag path to a view with no planet in it. Lower that height to
the free-look height with the free-look limit, never raising it, and
restore it on dispose. Above 1,000 km such a drag now orbits the globe,
as it already did above 7,500 km, at a similar rate, and a tilt drag
from the stars there tilts about the planet's edge or does nothing
instead of turning the camera. Drags that start on the planet are
unchanged.

src/app/application.test.mjs

@@ -359,7 +359,7 @@ test('trackpad pinch falls back to the original event when relay construction fa
 
 function freeLookFixture({ enableLook = true, height = 0 } = {}) {
   const listeners = new Set();
-  const controller = { enableLook };
+  const controller = { enableLook, minimumTrackBallHeight: 7_500_000 };
   const camera = { positionCartographic: { height } };
   const viewer = {
     camera,
@@ -399,6 +399,27 @@ test('free look follows camera height and is restored on dispose', () => {
   assert.equal(f.listeners.size, 0);
 });
 
+test('drags that start on the stars orbit above the free-look height', () => {
+  // Below Cesium's trackball height such a drag turns the camera in place.
+  const f = freeLookFixture({ height: 500 });
+  const dispose = installFreeLookHeightLimit(f.viewer);
+  assert.equal(
+    f.controller.minimumTrackBallHeight,
+    FREE_LOOK_MAX_HEIGHT_METERS,
+  );
+  dispose();
+  assert.equal(f.controller.minimumTrackBallHeight, 7_500_000);
+
+  const lower = freeLookFixture({ height: 500 });
+  lower.controller.minimumTrackBallHeight = 500_000;
+  installFreeLookHeightLimit(lower.viewer)();
+  assert.equal(
+    lower.controller.minimumTrackBallHeight,
+    500_000,
+    'never raised',
+  );
+});
+
 test('free look keeps a setting other code makes after it is installed', () => {
   const f = freeLookFixture({ height: 500 });
   const dispose = installFreeLookHeightLimit(f.viewer);