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/es-abstract/2017/ArraySpeciesCreate.js

@@ -0,0 +1,46 @@
+'use strict';
+
+var GetIntrinsic = require('get-intrinsic');
+
+var $Array = GetIntrinsic('%Array%');
+var $species = GetIntrinsic('%Symbol.species%', true);
+var $TypeError = require('es-errors/type');
+var isInteger = require('math-intrinsics/isInteger');
+var isObject = require('es-object-atoms/isObject');
+
+var Get = require('./Get');
+var IsArray = require('./IsArray');
+var IsConstructor = require('./IsConstructor');
+
+// https://262.ecma-international.org/6.0/#sec-arrayspeciescreate
+
+module.exports = function ArraySpeciesCreate(originalArray, length) {
+	if (!isInteger(length) || length < 0) {
+		throw new $TypeError('Assertion failed: length must be an integer >= 0');
+	}
+	var len = length === 0 ? 0 : length;
+	var C;
+	var isArray = IsArray(originalArray);
+	if (isArray) {
+		C = Get(originalArray, 'constructor');
+		// TODO: figure out how to make a cross-realm normal Array, a same-realm Array
+		// if (IsConstructor(C)) {
+		// 	if C is another realm's Array, C = undefined
+		// 	Object.getPrototypeOf(Object.getPrototypeOf(Object.getPrototypeOf(Array))) === null ?
+		// }
+		if ($species && isObject(C)) {
+			C = Get(C, $species);
+			if (C === null) {
+				C = void 0;
+			}
+		}
+	}
+	if (typeof C === 'undefined') {
+		return $Array(len);
+	}
+	if (!IsConstructor(C)) {
+		throw new $TypeError('C must be a constructor');
+	}
+	return new C(len); // Construct(C, len);
+};
+