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/@babel/runtime/helpers/esm/objectWithoutProperties.js

@@ -0,0 +1,13 @@
+import objectWithoutPropertiesLoose from "./objectWithoutPropertiesLoose.js";
+function _objectWithoutProperties(e, t) {
+  if (null == e) return {};
+  var o,
+    r,
+    i = objectWithoutPropertiesLoose(e, t);
+  if (Object.getOwnPropertySymbols) {
+    var n = Object.getOwnPropertySymbols(e);
+    for (r = 0; r < n.length; r++) o = n[r], -1 === t.indexOf(o) && {}.propertyIsEnumerable.call(e, o) && (i[o] = e[o]);
+  }
+  return i;
+}
+export { _objectWithoutProperties as default };