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/is-data-view/test/index.js

@@ -0,0 +1,60 @@
+'use strict';
+
+var test = require('tape');
+var isDataView = require('../');
+
+var hasToStringTag = require('has-tostringtag/shams')();
+var generators = require('make-generator-function')();
+var arrowFns = require('make-arrow-function').list();
+var forEach = require('for-each');
+var v = require('es-value-fixtures');
+var inspect = require('object-inspect');
+var availableTypedArrays = require('available-typed-arrays')();
+
+test('not DataViews', function (t) {
+	forEach([].concat(
+		// @ts-expect-error TS sucks at [].concat
+		v.primitives,
+		v.objects,
+		function () {},
+		generators,
+		arrowFns,
+		[]
+	), /** @type {(nonDV: unknown) => void} */ function (nonDV) {
+		t.equal(
+			isDataView(nonDV),
+			false,
+			inspect(nonDV) + ' is not a DataView'
+		);
+	});
+
+	forEach(availableTypedArrays, function (typedArray) {
+		var TA = global[typedArray];
+		var ta = new TA(8);
+		t.equal(isDataView(ta), false, inspect(ta) + ' is not a DataView');
+	});
+
+	t.end();
+});
+
+test('@@toStringTag', { skip: !hasToStringTag }, function (t) {
+	forEach(availableTypedArrays, function (typedArray) {
+		// @ts-expect-error
+		var fakeTypedArray = [];
+		// @ts-expect-error
+		fakeTypedArray[Symbol.toStringTag] = typedArray;
+		// @ts-expect-error
+		t.notOk(isDataView(fakeTypedArray), 'faked ' + typedArray + ' is not typed array');
+	});
+
+	t.end();
+});
+
+test('Data Views', { skip: typeof DataView !== 'function' }, function (t) {
+	var ab = new ArrayBuffer(1);
+	var dv = new DataView(ab);
+
+	t.equal(isDataView(dv), true, inspect(dv) + ' is a DataView');
+
+	t.end();
+});