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/2016/IterableToArrayLike.js

@@ -0,0 +1,34 @@
+'use strict';
+
+var getIteratorMethod = require('../helpers/getIteratorMethod');
+var AdvanceStringIndex = require('./AdvanceStringIndex');
+var GetIterator = require('./GetIterator');
+var GetMethod = require('./GetMethod');
+var IteratorStep = require('./IteratorStep');
+var IteratorValue = require('./IteratorValue');
+var ToObject = require('./ToObject');
+var ES = {
+	AdvanceStringIndex: AdvanceStringIndex,
+	GetMethod: GetMethod
+};
+
+// https://262.ecma-international.org/7.0/#sec-iterabletoarraylike
+
+module.exports = function IterableToArrayLike(items) {
+	var usingIterator = getIteratorMethod(ES, items);
+	if (typeof usingIterator !== 'undefined') {
+		var iterator = GetIterator(items, usingIterator);
+		var values = [];
+		var next = true;
+		while (next) {
+			next = IteratorStep(iterator);
+			if (next) {
+				var nextValue = IteratorValue(next);
+				values[values.length] = nextValue;
+			}
+		}
+		return values;
+	}
+
+	return ToObject(items);
+};