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/OrdinaryGetOwnProperty.js

@@ -0,0 +1,40 @@
+'use strict';
+
+var $gOPD = require('gopd');
+var $TypeError = require('es-errors/type');
+var isObject = require('es-object-atoms/isObject');
+var hasOwn = require('hasown');
+var callBound = require('call-bound');
+
+var $isEnumerable = callBound('Object.prototype.propertyIsEnumerable');
+
+var IsArray = require('./IsArray');
+var isPropertyKey = require('../helpers/isPropertyKey');
+var IsRegExp = require('./IsRegExp');
+var ToPropertyDescriptor = require('./ToPropertyDescriptor');
+
+// https://262.ecma-international.org/6.0/#sec-ordinarygetownproperty
+
+module.exports = function OrdinaryGetOwnProperty(O, P) {
+	if (!isObject(O)) {
+		throw new $TypeError('Assertion failed: O must be an Object');
+	}
+	if (!isPropertyKey(P)) {
+		throw new $TypeError('Assertion failed: P must be a Property Key');
+	}
+	if (!hasOwn(O, P)) {
+		return void 0;
+	}
+	if (!$gOPD) {
+		// ES3 / IE 8 fallback
+		var arrayLength = IsArray(O) && P === 'length';
+		var regexLastIndex = IsRegExp(O) && P === 'lastIndex';
+		return {
+			'[[Configurable]]': !(arrayLength || regexLastIndex),
+			'[[Enumerable]]': $isEnumerable(O, P),
+			'[[Value]]': O[P],
+			'[[Writable]]': true
+		};
+	}
+	return ToPropertyDescriptor($gOPD(O, P));
+};