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/regeneratorDefine.js

@@ -0,0 +1,22 @@
+function _regeneratorDefine(e, r, n, t) {
+  var i = Object.defineProperty;
+  try {
+    i({}, "", {});
+  } catch (e) {
+    i = 0;
+  }
+  _regeneratorDefine = function regeneratorDefine(e, r, n, t) {
+    function o(r, n) {
+      _regeneratorDefine(e, r, function (e) {
+        return this._invoke(r, n, e);
+      });
+    }
+    r ? i ? i(e, r, {
+      value: n,
+      enumerable: !t,
+      configurable: !t,
+      writable: !t
+    }) : e[r] = n : (o("next", 0), o("throw", 1), o("return", 2));
+  }, _regeneratorDefine(e, r, n, t);
+}
+export { _regeneratorDefine as default };