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/src/ui/status-bar.ts

@@ -0,0 +1,15 @@
+/**
+ * Status bar: status text + refresh button.
+ */
+
+/** Update the status text. */
+export function setStatus(text: string): void {
+  const el = document.getElementById('status-text');
+  if (el) el.textContent = text;
+}
+
+/** Set the refresh button click handler. */
+export function onRefreshClick(handler: () => void): void {
+  const btn = document.getElementById('refresh-btn');
+  if (btn) btn.addEventListener('click', handler);
+}