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-precaching/index.js

@@ -0,0 +1,34 @@
+/*
+  Copyright 2018 Google LLC
+
+  Use of this source code is governed by an MIT-style
+  license that can be found in the LICENSE file or at
+  https://opensource.org/licenses/MIT.
+*/
+import { addPlugins } from './addPlugins.js';
+import { addRoute } from './addRoute.js';
+import { cleanupOutdatedCaches } from './cleanupOutdatedCaches.js';
+import { createHandlerBoundToURL } from './createHandlerBoundToURL.js';
+import { getCacheKeyForURL } from './getCacheKeyForURL.js';
+import { matchPrecache } from './matchPrecache.js';
+import { precache } from './precache.js';
+import { precacheAndRoute } from './precacheAndRoute.js';
+import { PrecacheController } from './PrecacheController.js';
+import { PrecacheRoute } from './PrecacheRoute.js';
+import { PrecacheStrategy } from './PrecacheStrategy.js';
+import { PrecacheFallbackPlugin } from './PrecacheFallbackPlugin.js';
+import './_version.js';
+/**
+ * Most consumers of this module will want to use the
+ * {@link workbox-precaching.precacheAndRoute}
+ * method to add assets to the cache and respond to network requests with these
+ * cached assets.
+ *
+ * If you require more control over caching and routing, you can use the
+ * {@link workbox-precaching.PrecacheController}
+ * interface.
+ *
+ * @module workbox-precaching
+ */
+export { addPlugins, addRoute, cleanupOutdatedCaches, createHandlerBoundToURL, getCacheKeyForURL, matchPrecache, precache, precacheAndRoute, PrecacheController, PrecacheRoute, PrecacheStrategy, PrecacheFallbackPlugin, };
+export * from './_types.js';