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/pathe/dist/index.cjs

@@ -0,0 +1,23 @@
+'use strict';
+
+Object.defineProperty(exports, '__esModule', { value: true });
+
+const index = require('./shared/pathe.1f0a373c.cjs');
+
+
+
+exports.basename = index.basename;
+exports.default = index.path;
+exports.delimiter = index.delimiter;
+exports.dirname = index.dirname;
+exports.extname = index.extname;
+exports.format = index.format;
+exports.isAbsolute = index.isAbsolute;
+exports.join = index.join;
+exports.normalize = index.normalize;
+exports.normalizeString = index.normalizeString;
+exports.parse = index.parse;
+exports.relative = index.relative;
+exports.resolve = index.resolve;
+exports.sep = index.sep;
+exports.toNamespacedPath = index.toNamespacedPath;