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/uniq.js

@@ -0,0 +1,25 @@
+var baseUniq = require('./_baseUniq');
+
+/**
+ * Creates a duplicate-free version of an array, using
+ * [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero)
+ * for equality comparisons, in which only the first occurrence of each element
+ * is kept. The order of result values is determined by the order they occur
+ * in the array.
+ *
+ * @static
+ * @memberOf _
+ * @since 0.1.0
+ * @category Array
+ * @param {Array} array The array to inspect.
+ * @returns {Array} Returns the new duplicate free array.
+ * @example
+ *
+ * _.uniq([2, 1, 2]);
+ * // => [2, 1]
+ */
+function uniq(array) {
+  return (array && array.length) ? baseUniq(array) : [];
+}
+
+module.exports = uniq;