Move the wind's Cesium rendering into the Cesium adapter

The particle canvas, its GPU path and the relief shading move unchanged
from src/layers/wind/ to src/globe/cesium/; the adapter reads the Cesium
viewer itself, so the layer no longer hands one in.

src/globe/cesium/windFlow.js

@@ -1,7 +1,7 @@
 // Cesium's backend of the wind display: the wind renderer's streamlines
-// (src/layers/wind/rendering.js) over the viewer, read only once a Cesium globe draws.
+// over the viewer, read only once a Cesium globe draws.
 import * as Cesium from 'cesium';
-import { createWindRendering } from '../../layers/wind/rendering.js';
+import { createWindRendering } from './windRendering.js';
 
 export function createWindCesiumFlow(engine, { onStatusChange } = {}) {
   return createWindRendering({

src/globe/cesium/windGpuRendering.js

@@ -4,7 +4,7 @@ import {
   WIND_DISPLAY_HEIGHT_METERS,
   WIND_PATH_LIMIT,
   WIND_NARROW_PATH_LIMIT,
-} from './streamlines.js';
+} from '../../layers/wind/streamlines.js';
 
 const WIND_FADE_LOW_METERS = 15000;
 const WIND_FADE_HIGH_METERS = 60000;

src/globe/cesium/windRendering.js

@@ -1,7 +1,11 @@
-import { createWindRelief } from './relief.js';
-import { createWindGpuRendering } from './gpuRendering.js';
-import { advectParticle, sampleWind, sameWind } from './model.js';
-import { trailEraseAlpha, windTrailColor } from './fields.js';
+import { createWindRelief } from './windRelief.js';
+import { createWindGpuRendering } from './windGpuRendering.js';
+import {
+  advectParticle,
+  sampleWind,
+  sameWind,
+} from '../../layers/wind/model.js';
+import { trailEraseAlpha, windTrailColor } from '../../layers/wind/fields.js';
 
 /** The wind's streamlines on Cesium (the wind display's flow backend,
  * render/display.js, which draws the colour field): globe-projected surface

src/layers/wind/gpuRendering.test.mjs

@@ -1,6 +1,6 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
-import { createWindGpuRendering } from './gpuRendering.js';
+import { createWindGpuRendering } from '../../globe/cesium/windGpuRendering.js';
 import {
   BoundingSphere,
   Cartesian3,

src/layers/wind/relief.test.mjs

@@ -1,6 +1,6 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
-import { createWindRelief } from './relief.js';
+import { createWindRelief } from '../../globe/cesium/windRelief.js';
 
 function fixture({ material = undefined, normals = true } = {}) {
   const materials = [];

src/layers/wind/rendering.test.mjs

@@ -4,7 +4,7 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
 
-import { createWindRendering } from './rendering.js';
+import { createWindRendering } from '../../globe/cesium/windRendering.js';
 
 function event() {
   const listeners = new Set();