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/attempt.js

@@ -0,0 +1,35 @@
+var apply = require('./_apply'),
+    baseRest = require('./_baseRest'),
+    isError = require('./isError');
+
+/**
+ * Attempts to invoke `func`, returning either the result or the caught error
+ * object. Any additional arguments are provided to `func` when it's invoked.
+ *
+ * @static
+ * @memberOf _
+ * @since 3.0.0
+ * @category Util
+ * @param {Function} func The function to attempt.
+ * @param {...*} [args] The arguments to invoke `func` with.
+ * @returns {*} Returns the `func` result or error object.
+ * @example
+ *
+ * // Avoid throwing errors for invalid selectors.
+ * var elements = _.attempt(function(selector) {
+ *   return document.querySelectorAll(selector);
+ * }, '>_>');
+ *
+ * if (_.isError(elements)) {
+ *   elements = [];
+ * }
+ */
+var attempt = baseRest(function(func, args) {
+  try {
+    return apply(func, undefined, args);
+  } catch (e) {
+    return isError(e) ? e : new Error(e);
+  }
+});
+
+module.exports = attempt;