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/2023/IteratorNext.js

@@ -0,0 +1,28 @@
+'use strict';
+
+var $TypeError = require('es-errors/type');
+var isObject = require('es-object-atoms/isObject');
+
+var Call = require('./Call');
+
+var isIteratorRecord = require('../helpers/records/iterator-record-2023');
+
+// https://262.ecma-international.org/14.0/#sec-iteratornext
+
+module.exports = function IteratorNext(iteratorRecord) {
+	if (!isIteratorRecord(iteratorRecord)) {
+		throw new $TypeError('Assertion failed: `iteratorRecord` must be an Iterator Record'); // step 1
+	}
+
+	var result;
+	if (arguments.length < 2) { // step 1
+		result = Call(iteratorRecord['[[NextMethod]]'], iteratorRecord['[[Iterator]]']); // step 1.a
+	} else { // step 2
+		result = Call(iteratorRecord['[[NextMethod]]'], iteratorRecord['[[Iterator]]'], [arguments[1]]); // step 2.a
+	}
+
+	if (!isObject(result)) {
+		throw new $TypeError('iterator next must return an object'); // step 3
+	}
+	return result; // step 4
+};