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/isArrayLike.js

@@ -0,0 +1,33 @@
+var isFunction = require('./isFunction'),
+    isLength = require('./isLength');
+
+/**
+ * Checks if `value` is array-like. A value is considered array-like if it's
+ * not a function and has a `value.length` that's an integer greater than or
+ * equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.
+ *
+ * @static
+ * @memberOf _
+ * @since 4.0.0
+ * @category Lang
+ * @param {*} value The value to check.
+ * @returns {boolean} Returns `true` if `value` is array-like, else `false`.
+ * @example
+ *
+ * _.isArrayLike([1, 2, 3]);
+ * // => true
+ *
+ * _.isArrayLike(document.body.children);
+ * // => true
+ *
+ * _.isArrayLike('abc');
+ * // => true
+ *
+ * _.isArrayLike(_.noop);
+ * // => false
+ */
+function isArrayLike(value) {
+  return value != null && isLength(value.length) && !isFunction(value);
+}
+
+module.exports = isArrayLike;