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/object-inspect/test/browser/dom.js

@@ -0,0 +1,15 @@
+var inspect = require('../../');
+var test = require('tape');
+
+test('dom element', function (t) {
+    t.plan(1);
+
+    var d = document.createElement('div');
+    d.setAttribute('id', 'beep');
+    d.innerHTML = '<b>wooo</b><i>iiiii</i>';
+
+    t.equal(
+        inspect([d, { a: 3, b: 4, c: [5, 6, [7, [8, [9]]]] }]),
+        '[ <div id="beep">...</div>, { a: 3, b: 4, c: [ 5, 6, [ 7, [ 8, [Object] ] ] ] } ]'
+    );
+});