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/dunder-proto/test/get.js

@@ -0,0 +1,34 @@
+'use strict';
+
+var test = require('tape');
+
+var getDunderProto = require('../get');
+
+test('getDunderProto', { skip: !getDunderProto }, function (t) {
+	if (!getDunderProto) {
+		throw 'should never happen; this is just for type narrowing'; // eslint-disable-line no-throw-literal
+	}
+
+	// @ts-expect-error
+	t['throws'](function () { getDunderProto(); }, TypeError, 'throws if no argument');
+	// @ts-expect-error
+	t['throws'](function () { getDunderProto(undefined); }, TypeError, 'throws with undefined');
+	// @ts-expect-error
+	t['throws'](function () { getDunderProto(null); }, TypeError, 'throws with null');
+
+	t.equal(getDunderProto({}), Object.prototype);
+	t.equal(getDunderProto([]), Array.prototype);
+	t.equal(getDunderProto(function () {}), Function.prototype);
+	t.equal(getDunderProto(/./g), RegExp.prototype);
+	t.equal(getDunderProto(42), Number.prototype);
+	t.equal(getDunderProto(true), Boolean.prototype);
+	t.equal(getDunderProto('foo'), String.prototype);
+
+	t.end();
+});
+
+test('no dunder proto', { skip: !!getDunderProto }, function (t) {
+	t.notOk('__proto__' in Object.prototype, 'no __proto__ in Object.prototype');
+
+	t.end();
+});