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/dist/environments.d.ts

@@ -0,0 +1,21 @@
+import { E as Environment } from './chunks/environment.LoooBwUu.js';
+export { a as EnvironmentReturn, V as VmEnvironmentReturn } from './chunks/environment.LoooBwUu.js';
+
+declare const environments: {
+    node: Environment;
+    jsdom: Environment;
+    'happy-dom': Environment;
+    'edge-runtime': Environment;
+};
+
+interface PopulateOptions {
+    bindFunctions?: boolean;
+    additionalKeys?: string[];
+}
+declare function populateGlobal(global: any, win: any, options?: PopulateOptions): {
+    keys: Set<string>;
+    skipKeys: string[];
+    originals: Map<string | symbol, any>;
+};
+
+export { Environment, environments as builtinEnvironments, populateGlobal };