feat(layers): add FAA drone restrictions airspace layer

Show US prohibited and restricted special-use airspace from the keyless
FAA SUA FeatureServer as an off-by-default Infrastructure layer, with
share-link token 3 and an informational-only disclaimer.

src/app/layers/droneAirspace.js

@@ -0,0 +1,22 @@
+import * as Cesium from 'cesium';
+import { createDroneAirspaceLayer } from '../../layers/droneAirspace/index.js';
+import * as picking from '../../data/pickRegistry.js';
+import * as overlays from '../../overlays/worldOverlay.js';
+import { isPointerFree } from '../../data/inputOwnership.js';
+
+/** Wire FAA special-use airspace into the application catalog. */
+export function createApplicationDroneAirspace(options) {
+  return createDroneAirspaceLayer({
+    overlayHost: {
+      setEntries: overlays.setOverlayEntries,
+      setVisible: overlays.setOverlaySourceVisible,
+      clearSource: overlays.clearOverlaySource,
+      hitTest: overlays.hitTestWorldOverlay,
+    },
+    screenSpaceEventHandlerFactory: (viewer) =>
+      new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas),
+    picking,
+    pointer: { isPointerFree },
+    ...options,
+  });
+}