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/preset-env/lib/targets-parser.js

@@ -0,0 +1,20 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+Object.defineProperty(exports, "default", {
+  enumerable: true,
+  get: function () {
+    return _helperCompilationTargets.default;
+  }
+});
+Object.defineProperty(exports, "isBrowsersQueryValid", {
+  enumerable: true,
+  get: function () {
+    return _helperCompilationTargets.isBrowsersQueryValid;
+  }
+});
+var _helperCompilationTargets = require("@babel/helper-compilation-targets");
+
+//# sourceMappingURL=targets-parser.js.map