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/@vitest/mocker/dist/register.js

@@ -0,0 +1,40 @@
+import { spyOn } from '@vitest/spy';
+import { M as ModuleMocker, r as rpc, c as createCompilerHints, h as hot } from './chunk-mocker.js';
+import './index.js';
+import './chunk-registry.js';
+import './chunk-pathe.ff20891b.js';
+
+function registerModuleMocker(interceptor) {
+  const mocker = new ModuleMocker(
+    interceptor(__VITEST_GLOBAL_THIS_ACCESSOR__),
+    {
+      resolveId(id, importer) {
+        return rpc("vitest:mocks:resolveId", { id, importer });
+      },
+      resolveMock(id, importer, options) {
+        return rpc("vitest:mocks:resolveMock", { id, importer, options });
+      },
+      async invalidate(ids) {
+        return rpc("vitest:mocks:invalidate", { ids });
+      }
+    },
+    spyOn,
+    {
+      root: __VITEST_MOCKER_ROOT__
+    }
+  );
+  globalThis[__VITEST_GLOBAL_THIS_ACCESSOR__] = mocker;
+  registerNativeFactoryResolver(mocker);
+  return createCompilerHints({
+    globalThisKey: __VITEST_GLOBAL_THIS_ACCESSOR__
+  });
+}
+function registerNativeFactoryResolver(mocker) {
+  hot.on("vitest:interceptor:resolve", async (url) => {
+    const exports = await mocker.resolveFactoryModule(url);
+    const keys = Object.keys(exports);
+    hot.send("vitest:interceptor:resolved", { url, keys });
+  });
+}
+
+export { registerModuleMocker, registerNativeFactoryResolver };