Upgrade eslint to v10 & uppy to v6

src/components/ProjectMap.vue

@@ -155,6 +155,10 @@ export default {
 		addTerrain() {
 			// MapLibre terrain's fog matrix is only implemented for Mercator.
 			this.map.setProjection({type: 'mercator'});
+			//One shared raster-dem source feeds both the 3D elevation mesh
+			//(setTerrain) and the hillshade layer below - they used to be two
+			//separate sources pointed at the identical tile URL, which meant
+			//every DEM tile was downloaded and decoded twice per viewport.
 			if(!this.map.getSource('terrain-dem')) {
 				this.map.addSource('terrain-dem', {
 					type: 'raster-dem',
@@ -164,20 +168,11 @@ export default {
 					encoding: 'terrarium'
 				});
 			}
-			if(!this.map.getSource('hillshade-dem')) {
-				this.map.addSource('hillshade-dem', {
-					type: 'raster-dem',
-					tiles: ['https://s3.amazonaws.com/elevation-tiles-prod/terrarium/{z}/{x}/{y}.png'],
-					tileSize: 256,
-					maxzoom: 13,
-					encoding: 'terrarium'
-				});
-			}
 			if(!this.map.getLayer('terrain-hillshade')) {
 				this.map.addLayer({
 					id: 'terrain-hillshade',
 					type: 'hillshade',
-					source: 'hillshade-dem',
+					source: 'terrain-dem',
 					paint: {
 						'hillshade-exaggeration': 0.35,
 						'hillshade-shadow-color': '#2d342b',
@@ -191,7 +186,6 @@ export default {
 			if(!this.map) return;
 			if(this.map.getTerrain()) this.map.setTerrain(null);
 			if(this.map.getLayer('terrain-hillshade')) this.map.removeLayer('terrain-hillshade');
-			if(this.map.getSource('hillshade-dem')) this.map.removeSource('hillshade-dem');
 			if(this.map.getSource('terrain-dem')) this.map.removeSource('terrain-dem');
 			this.map.setProjection({type: 'globe'});
 		},