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/loupe/lib/map.js

@@ -0,0 +1,22 @@
+import { inspectList } from './helpers.js';
+function inspectMapEntry([key, value], options) {
+    options.truncate -= 4;
+    key = options.inspect(key, options);
+    options.truncate -= key.length;
+    value = options.inspect(value, options);
+    return `${key} => ${value}`;
+}
+// IE11 doesn't support `map.entries()`
+function mapToEntries(map) {
+    const entries = [];
+    map.forEach((value, key) => {
+        entries.push([key, value]);
+    });
+    return entries;
+}
+export default function inspectMap(map, options) {
+    if (map.size === 0)
+        return 'Map{}';
+    options.truncate -= 7;
+    return `Map{ ${inspectList(mapToEntries(map), options, inspectMapEntry)} }`;
+}