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/_basePullAt.js

@@ -0,0 +1,37 @@
+var baseUnset = require('./_baseUnset'),
+    isIndex = require('./_isIndex');
+
+/** Used for built-in method references. */
+var arrayProto = Array.prototype;
+
+/** Built-in value references. */
+var splice = arrayProto.splice;
+
+/**
+ * The base implementation of `_.pullAt` without support for individual
+ * indexes or capturing the removed elements.
+ *
+ * @private
+ * @param {Array} array The array to modify.
+ * @param {number[]} indexes The indexes of elements to remove.
+ * @returns {Array} Returns `array`.
+ */
+function basePullAt(array, indexes) {
+  var length = array ? indexes.length : 0,
+      lastIndex = length - 1;
+
+  while (length--) {
+    var index = indexes[length];
+    if (length == lastIndex || index !== previous) {
+      var previous = index;
+      if (isIndex(index)) {
+        splice.call(array, index, 1);
+      } else {
+        baseUnset(array, index);
+      }
+    }
+  }
+  return array;
+}
+
+module.exports = basePullAt;