Add progressive web app companion for cross-platform access

Vite + TypeScript PWA that mirrors the Android app's core features:
- Pre-processed shelter data (build-time UTM33N→WGS84 conversion)
- Leaflet map with shelter markers, user location, and offline tiles
- Canvas compass arrow (ported from DirectionArrowView.kt)
- IndexedDB shelter cache with 7-day staleness check
- Service worker with CacheFirst tiles and precached app shell
- i18n for en, nb, nn (ported from Android strings.xml)
- iOS/Android compass handling with low-pass filter
- Respects user map interaction (no auto-snap on pan/zoom)
- Build revision cache-breaker for reliable SW updates

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pwa/node_modules/leaflet/src/layer/vector/Circle.js

@@ -0,0 +1,113 @@
+import {CircleMarker} from './CircleMarker';
+import {Path} from './Path';
+import * as Util from '../../core/Util';
+import {toLatLng} from '../../geo/LatLng';
+import {LatLngBounds} from '../../geo/LatLngBounds';
+import {Earth} from '../../geo/crs/CRS.Earth';
+
+
+/*
+ * @class Circle
+ * @aka L.Circle
+ * @inherits CircleMarker
+ *
+ * A class for drawing circle overlays on a map. Extends `CircleMarker`.
+ *
+ * It's an approximation and starts to diverge from a real circle closer to poles (due to projection distortion).
+ *
+ * @example
+ *
+ * ```js
+ * L.circle([50.5, 30.5], {radius: 200}).addTo(map);
+ * ```
+ */
+
+export var Circle = CircleMarker.extend({
+
+	initialize: function (latlng, options, legacyOptions) {
+		if (typeof options === 'number') {
+			// Backwards compatibility with 0.7.x factory (latlng, radius, options?)
+			options = Util.extend({}, legacyOptions, {radius: options});
+		}
+		Util.setOptions(this, options);
+		this._latlng = toLatLng(latlng);
+
+		if (isNaN(this.options.radius)) { throw new Error('Circle radius cannot be NaN'); }
+
+		// @section
+		// @aka Circle options
+		// @option radius: Number; Radius of the circle, in meters.
+		this._mRadius = this.options.radius;
+	},
+
+	// @method setRadius(radius: Number): this
+	// Sets the radius of a circle. Units are in meters.
+	setRadius: function (radius) {
+		this._mRadius = radius;
+		return this.redraw();
+	},
+
+	// @method getRadius(): Number
+	// Returns the current radius of a circle. Units are in meters.
+	getRadius: function () {
+		return this._mRadius;
+	},
+
+	// @method getBounds(): LatLngBounds
+	// Returns the `LatLngBounds` of the path.
+	getBounds: function () {
+		var half = [this._radius, this._radiusY || this._radius];
+
+		return new LatLngBounds(
+			this._map.layerPointToLatLng(this._point.subtract(half)),
+			this._map.layerPointToLatLng(this._point.add(half)));
+	},
+
+	setStyle: Path.prototype.setStyle,
+
+	_project: function () {
+
+		var lng = this._latlng.lng,
+		    lat = this._latlng.lat,
+		    map = this._map,
+		    crs = map.options.crs;
+
+		if (crs.distance === Earth.distance) {
+			var d = Math.PI / 180,
+			    latR = (this._mRadius / Earth.R) / d,
+			    top = map.project([lat + latR, lng]),
+			    bottom = map.project([lat - latR, lng]),
+			    p = top.add(bottom).divideBy(2),
+			    lat2 = map.unproject(p).lat,
+			    lngR = Math.acos((Math.cos(latR * d) - Math.sin(lat * d) * Math.sin(lat2 * d)) /
+			            (Math.cos(lat * d) * Math.cos(lat2 * d))) / d;
+
+			if (isNaN(lngR) || lngR === 0) {
+				lngR = latR / Math.cos(Math.PI / 180 * lat); // Fallback for edge case, #2425
+			}
+
+			this._point = p.subtract(map.getPixelOrigin());
+			this._radius = isNaN(lngR) ? 0 : p.x - map.project([lat2, lng - lngR]).x;
+			this._radiusY = p.y - top.y;
+
+		} else {
+			var latlng2 = crs.unproject(crs.project(this._latlng).subtract([this._mRadius, 0]));
+
+			this._point = map.latLngToLayerPoint(this._latlng);
+			this._radius = this._point.x - map.latLngToLayerPoint(latlng2).x;
+		}
+
+		this._updateBounds();
+	}
+});
+
+// @factory L.circle(latlng: LatLng, options?: Circle options)
+// Instantiates a circle object given a geographical point, and an options object
+// which contains the circle radius.
+// @alternative
+// @factory L.circle(latlng: LatLng, radius: Number, options?: Circle options)
+// Obsolete way of instantiating a circle, for compatibility with 0.7.x code.
+// Do not use in new applications or plugins.
+export function circle(latlng, options, legacyOptions) {
+	return new Circle(latlng, options, legacyOptions);
+}