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/workbox-build/build/lib/get-file-details.d.ts

@@ -0,0 +1,14 @@
+import { GlobPartial } from '../types';
+interface FileDetails {
+    file: string;
+    hash: string;
+    size: number;
+}
+export declare function getFileDetails({ globDirectory, globFollow, globIgnores, globPattern, }: Omit<GlobPartial, 'globDirectory' | 'globPatterns' | 'templatedURLs'> & {
+    globDirectory: string;
+    globPattern: string;
+}): {
+    globbedFileDetails: Array<FileDetails>;
+    warning: string;
+};
+export {};