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/lodash/shuffle.js

@@ -0,0 +1,25 @@
+var arrayShuffle = require('./_arrayShuffle'),
+    baseShuffle = require('./_baseShuffle'),
+    isArray = require('./isArray');
+
+/**
+ * Creates an array of shuffled values, using a version of the
+ * [Fisher-Yates shuffle](https://en.wikipedia.org/wiki/Fisher-Yates_shuffle).
+ *
+ * @static
+ * @memberOf _
+ * @since 0.1.0
+ * @category Collection
+ * @param {Array|Object} collection The collection to shuffle.
+ * @returns {Array} Returns the new shuffled array.
+ * @example
+ *
+ * _.shuffle([1, 2, 3, 4]);
+ * // => [4, 1, 3, 2]
+ */
+function shuffle(collection) {
+  var func = isArray(collection) ? arrayShuffle : baseShuffle;
+  return func(collection);
+}
+
+module.exports = shuffle;