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/2015/GetV.js

@@ -0,0 +1,23 @@
+'use strict';
+
+var $TypeError = require('es-errors/type');
+
+var inspect = require('object-inspect');
+
+var isPropertyKey = require('../helpers/isPropertyKey');
+// var ToObject = require('./ToObject');
+
+// https://262.ecma-international.org/6.0/#sec-getv
+
+module.exports = function GetV(V, P) {
+	// 7.3.2.1
+	if (!isPropertyKey(P)) {
+		throw new $TypeError('Assertion failed: P is not a Property Key, got ' + inspect(P));
+	}
+
+	// 7.3.2.2-3
+	// var O = ToObject(V);
+
+	// 7.3.2.4
+	return V[P];
+};