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/vitest/dist/chunks/spy.Cf_4R5Oe.js

@@ -0,0 +1,22 @@
+import * as spy$1 from '@vitest/spy';
+
+function _mergeNamespaces(n, m) {
+	m.forEach(function (e) {
+		e && typeof e !== 'string' && !Array.isArray(e) && Object.keys(e).forEach(function (k) {
+			if (k !== 'default' && !(k in n)) {
+				var d = Object.getOwnPropertyDescriptor(e, k);
+				Object.defineProperty(n, k, d.get ? d : {
+					enumerable: true,
+					get: function () { return e[k]; }
+				});
+			}
+		});
+	});
+	return Object.freeze(n);
+}
+
+var spy = /*#__PURE__*/_mergeNamespaces({
+	__proto__: null
+}, [spy$1]);
+
+export { spy as s };