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/_baseIsEqual.js

@@ -0,0 +1,28 @@
+var baseIsEqualDeep = require('./_baseIsEqualDeep'),
+    isObjectLike = require('./isObjectLike');
+
+/**
+ * The base implementation of `_.isEqual` which supports partial comparisons
+ * and tracks traversed objects.
+ *
+ * @private
+ * @param {*} value The value to compare.
+ * @param {*} other The other value to compare.
+ * @param {boolean} bitmask The bitmask flags.
+ *  1 - Unordered comparison
+ *  2 - Partial comparison
+ * @param {Function} [customizer] The function to customize comparisons.
+ * @param {Object} [stack] Tracks traversed `value` and `other` objects.
+ * @returns {boolean} Returns `true` if the values are equivalent, else `false`.
+ */
+function baseIsEqual(value, other, bitmask, customizer, stack) {
+  if (value === other) {
+    return true;
+  }
+  if (value == null || other == null || (!isObjectLike(value) && !isObjectLike(other))) {
+    return value !== value && other !== other;
+  }
+  return baseIsEqualDeep(value, other, bitmask, customizer, baseIsEqual, stack);
+}
+
+module.exports = baseIsEqual;