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/helper-module-transforms/lib/rewrite-this.js

@@ -0,0 +1,22 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = rewriteThis;
+var _core = require("@babel/core");
+var _traverse = require("@babel/traverse");
+let rewriteThisVisitor;
+function rewriteThis(programPath) {
+  if (!rewriteThisVisitor) {
+    rewriteThisVisitor = _traverse.visitors.environmentVisitor({
+      ThisExpression(path) {
+        path.replaceWith(_core.types.unaryExpression("void", _core.types.numericLiteral(0), true));
+      }
+    });
+    rewriteThisVisitor.noScope = true;
+  }
+  (0, _traverse.default)(programPath.node, rewriteThisVisitor);
+}
+
+//# sourceMappingURL=rewrite-this.js.map