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/has-symbols/test/index.js

@@ -0,0 +1,22 @@
+'use strict';
+
+var test = require('tape');
+var hasSymbols = require('../');
+var runSymbolTests = require('./tests');
+
+test('interface', function (t) {
+	t.equal(typeof hasSymbols, 'function', 'is a function');
+	t.equal(typeof hasSymbols(), 'boolean', 'returns a boolean');
+	t.end();
+});
+
+test('Symbols are supported', { skip: !hasSymbols() }, function (t) {
+	runSymbolTests(t);
+	t.end();
+});
+
+test('Symbols are not supported', { skip: hasSymbols() }, function (t) {
+	t.equal(typeof Symbol, 'undefined', 'global Symbol is undefined');
+	t.equal(typeof Object.getOwnPropertySymbols, 'undefined', 'Object.getOwnPropertySymbols does not exist');
+	t.end();
+});