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/toPairsIn.js

@@ -0,0 +1,30 @@
+var createToPairs = require('./_createToPairs'),
+    keysIn = require('./keysIn');
+
+/**
+ * Creates an array of own and inherited enumerable string keyed-value pairs
+ * for `object` which can be consumed by `_.fromPairs`. If `object` is a map
+ * or set, its entries are returned.
+ *
+ * @static
+ * @memberOf _
+ * @since 4.0.0
+ * @alias entriesIn
+ * @category Object
+ * @param {Object} object The object to query.
+ * @returns {Array} Returns the key-value pairs.
+ * @example
+ *
+ * function Foo() {
+ *   this.a = 1;
+ *   this.b = 2;
+ * }
+ *
+ * Foo.prototype.c = 3;
+ *
+ * _.toPairsIn(new Foo);
+ * // => [['a', 1], ['b', 2], ['c', 3]] (iteration order is not guaranteed)
+ */
+var toPairsIn = createToPairs(keysIn);
+
+module.exports = toPairsIn;