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/_nodeUtil.js

@@ -0,0 +1,30 @@
+var freeGlobal = require('./_freeGlobal');
+
+/** Detect free variable `exports`. */
+var freeExports = typeof exports == 'object' && exports && !exports.nodeType && exports;
+
+/** Detect free variable `module`. */
+var freeModule = freeExports && typeof module == 'object' && module && !module.nodeType && module;
+
+/** Detect the popular CommonJS extension `module.exports`. */
+var moduleExports = freeModule && freeModule.exports === freeExports;
+
+/** Detect free variable `process` from Node.js. */
+var freeProcess = moduleExports && freeGlobal.process;
+
+/** Used to access faster Node.js helpers. */
+var nodeUtil = (function() {
+  try {
+    // Use `util.types` for Node.js 10+.
+    var types = freeModule && freeModule.require && freeModule.require('util').types;
+
+    if (types) {
+      return types;
+    }
+
+    // Legacy `process.binding('util')` for Node.js < 10.
+    return freeProcess && freeProcess.binding && freeProcess.binding('util');
+  } catch (e) {}
+}());
+
+module.exports = nodeUtil;