Draw nine layers' fills through engine.ground, one display each

Earthquakes, air quality, GNSS Integrity, fire perimeters, Prohibited &
Restricted Airspace, Active Fires, S2 GhostMaps, cyclone advisories and
submarine cables each have one render/display.js on the globe contract;
their render/cesium* and render/navara* files go. Their discs, cells,
polygons and corridors are engine.ground sets, so on Navara they come from
the one ground screen pass with exact colours instead of nine hand-written
classification passes and lit SDK vector layers. Cesium's look stays the
reference:

- Earthquake and air-quality discs have no outline (Cesium drew none on
  clamped ellipses); earthquake discs can now be picked on Navara too.
- Perimeters, drone zones and GhostMaps polygons outline their outer
  ring only, as Cesium did.
- GNSS cells stay out of the pick pass; cyclone cones, tracks and centres
  are culled by a port of Cesium's horizon occluder.
- Submarine cables are one ground corridor set, as Cesium batched them;
  landing points, tips and stems are movers and lines.
- FIRMS glows are a sprite set and its cells a ground set. The far-zoom
  heat raster, which no primitive draws yet, sits behind one seam,
  render/heatField.js, with a Cesium and a Navara backend.

The shared Navara ground helpers that only these layers used go
(navaraGroundCells, the cell and ground geometry, the zone renderers), as
does the ground prototype script.

Coupling: layer renderer lines fall from 1636/6953 to 1011/4832
(Cesium/Navara), Navara ground passes from 7 to 5, Cesium-importing files
from 65 to 53, engine.extensions reads from 26 to 19.

src/layers/droneAirspace/index.js

@@ -1,6 +1,6 @@
 import * as geo from '../../geo/index.js';
 import { msg, t } from '../../i18n/index.js';
-import { createZonesCesiumRenderer } from '../shared/render/cesiumZones.js';
+import { createDroneAirspaceDisplay } from './render/display.js';
 import {
   DRONE_AIRSPACE_OVERLAY_SOURCE_ID,
   droneAirspaceAnchorDegrees,
@@ -11,20 +11,6 @@ export { normalizeDroneAirspaceSnapshot } from './records.js';
 export { createDroneAirspaceSource } from './source.js';
 export * from './cards.js';
 
-/** The zones on a Cesium globe (the default renderer). */
-export function createDroneAirspaceCesiumRenderer({
-  viewer,
-  screenSpaceEventHandlerFactory,
-}) {
-  return createZonesCesiumRenderer({
-    viewer,
-    screenSpaceEventHandlerFactory,
-    name: 'drone-airspace',
-    idPrefix: 'drone-airspace',
-    colorOf: (row) => droneAirspaceAccent(row.typeCode),
-  });
-}
-
 /**
  * FNV-1a over a zone's rings: a short, deterministic fingerprint so a
  * boundary change with unchanged attributes still alters the refresh signature.
@@ -50,10 +36,9 @@ const CARD_HOST_OPTIONS = Object.freeze({
 export function createDroneAirspaceLayer({
   source,
   overlayHost = null,
-  screenSpaceEventHandlerFactory = null,
   picking = null,
   pointer = null,
-  createRenderer = createDroneAirspaceCesiumRenderer,
+  createRenderer = ({ engine }) => createDroneAirspaceDisplay(engine),
 } = {}) {
   if (typeof source?.getSnapshot !== 'function')
     throw new TypeError('Drone airspace requires a snapshot source');
@@ -74,8 +59,7 @@ export function createDroneAirspaceLayer({
   /** @type {Map<string, {stableId: string, anchor: {lon: number, lat: number}}>} */
   const _rowById = new Map();
 
-  const canSelect = () =>
-    overlayHost && screenSpaceEventHandlerFactory && picking;
+  const canSelect = () => overlayHost && picking;
 
   function publishSelectedCard() {
     if (!canSelect() || !renderer) return;
@@ -172,7 +156,7 @@ export function createDroneAirspaceLayer({
         throw new Error('Drone airspace layer is already initialized');
       initialized = true;
       try {
-        if (viewer || engine) this.attachRenderer(viewer, { engine });
+        if (engine) this.attachRenderer(viewer, { engine });
       } catch (error) {
         this.destroy();
         throw error;
@@ -184,11 +168,7 @@ export function createDroneAirspaceLayer({
     attachRenderer(viewer, { engine = null } = {}) {
       if (!initialized || renderer)
         throw new Error('Invalid drone airspace scene attachment');
-      renderer = createRenderer({
-        viewer,
-        engine,
-        screenSpaceEventHandlerFactory,
-      });
+      renderer = createRenderer({ engine });
       renderer.setVisible(_enabled);
       if (_rows.length) renderer.replace(_rows);
       if (_enabled) {