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/before.js

@@ -0,0 +1,40 @@
+var toInteger = require('./toInteger');
+
+/** Error message constants. */
+var FUNC_ERROR_TEXT = 'Expected a function';
+
+/**
+ * Creates a function that invokes `func`, with the `this` binding and arguments
+ * of the created function, while it's called less than `n` times. Subsequent
+ * calls to the created function return the result of the last `func` invocation.
+ *
+ * @static
+ * @memberOf _
+ * @since 3.0.0
+ * @category Function
+ * @param {number} n The number of calls at which `func` is no longer invoked.
+ * @param {Function} func The function to restrict.
+ * @returns {Function} Returns the new restricted function.
+ * @example
+ *
+ * jQuery(element).on('click', _.before(5, addContactToList));
+ * // => Allows adding up to 4 contacts to the list.
+ */
+function before(n, func) {
+  var result;
+  if (typeof func != 'function') {
+    throw new TypeError(FUNC_ERROR_TEXT);
+  }
+  n = toInteger(n);
+  return function() {
+    if (--n > 0) {
+      result = func.apply(this, arguments);
+    }
+    if (n <= 1) {
+      func = undefined;
+    }
+    return result;
+  };
+}
+
+module.exports = before;