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/isFinite.js

@@ -0,0 +1,36 @@
+var root = require('./_root');
+
+/* Built-in method references for those with the same name as other `lodash` methods. */
+var nativeIsFinite = root.isFinite;
+
+/**
+ * Checks if `value` is a finite primitive number.
+ *
+ * **Note:** This method is based on
+ * [`Number.isFinite`](https://mdn.io/Number/isFinite).
+ *
+ * @static
+ * @memberOf _
+ * @since 0.1.0
+ * @category Lang
+ * @param {*} value The value to check.
+ * @returns {boolean} Returns `true` if `value` is a finite number, else `false`.
+ * @example
+ *
+ * _.isFinite(3);
+ * // => true
+ *
+ * _.isFinite(Number.MIN_VALUE);
+ * // => true
+ *
+ * _.isFinite(Infinity);
+ * // => false
+ *
+ * _.isFinite('3');
+ * // => false
+ */
+function isFinite(value) {
+  return typeof value == 'number' && nativeIsFinite(value);
+}
+
+module.exports = isFinite;