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/_compareMultiple.js

@@ -0,0 +1,44 @@
+var compareAscending = require('./_compareAscending');
+
+/**
+ * Used by `_.orderBy` to compare multiple properties of a value to another
+ * and stable sort them.
+ *
+ * If `orders` is unspecified, all values are sorted in ascending order. Otherwise,
+ * specify an order of "desc" for descending or "asc" for ascending sort order
+ * of corresponding values.
+ *
+ * @private
+ * @param {Object} object The object to compare.
+ * @param {Object} other The other object to compare.
+ * @param {boolean[]|string[]} orders The order to sort by for each property.
+ * @returns {number} Returns the sort order indicator for `object`.
+ */
+function compareMultiple(object, other, orders) {
+  var index = -1,
+      objCriteria = object.criteria,
+      othCriteria = other.criteria,
+      length = objCriteria.length,
+      ordersLength = orders.length;
+
+  while (++index < length) {
+    var result = compareAscending(objCriteria[index], othCriteria[index]);
+    if (result) {
+      if (index >= ordersLength) {
+        return result;
+      }
+      var order = orders[index];
+      return result * (order == 'desc' ? -1 : 1);
+    }
+  }
+  // Fixes an `Array#sort` bug in the JS engine embedded in Adobe applications
+  // that causes it, under certain circumstances, to provide the same value for
+  // `object` and `other`. See https://github.com/jashkenas/underscore/pull/1247
+  // for more details.
+  //
+  // This also ensures a stable sort in V8 and other engines.
+  // See https://bugs.chromium.org/p/v8/issues/detail?id=90 for more details.
+  return object.index - other.index;
+}
+
+module.exports = compareMultiple;