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/interopRequireWildcard.js

@@ -0,0 +1,22 @@
+var _typeof = require("./typeof.js")["default"];
+function _interopRequireWildcard(e, t) {
+  if ("function" == typeof WeakMap) var r = new WeakMap(),
+    n = new WeakMap();
+  return (module.exports = _interopRequireWildcard = function _interopRequireWildcard(e, t) {
+    if (!t && e && e.__esModule) return e;
+    var o,
+      i,
+      f = {
+        __proto__: null,
+        "default": e
+      };
+    if (null === e || "object" != _typeof(e) && "function" != typeof e) return f;
+    if (o = t ? n : r) {
+      if (o.has(e)) return o.get(e);
+      o.set(e, f);
+    }
+    for (var _t in e) "default" !== _t && {}.hasOwnProperty.call(e, _t) && ((i = (o = Object.defineProperty) && Object.getOwnPropertyDescriptor(e, _t)) && (i.get || i.set) ? o(f, _t, i) : f[_t] = e[_t]);
+    return f;
+  }, module.exports.__esModule = true, module.exports["default"] = module.exports)(e, t);
+}
+module.exports = _interopRequireWildcard, module.exports.__esModule = true, module.exports["default"] = module.exports;