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/shebang-command/index.js

@@ -0,0 +1,19 @@
+'use strict';
+const shebangRegex = require('shebang-regex');
+
+module.exports = (string = '') => {
+	const match = string.match(shebangRegex);
+
+	if (!match) {
+		return null;
+	}
+
+	const [path, argument] = match[0].replace(/#! ?/, '').split(' ');
+	const binary = path.split('/').pop();
+
+	if (binary === 'env') {
+		return argument;
+	}
+
+	return argument ? `${binary} ${argument}` : binary;
+};