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/js-tokens/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "js-tokens",
+  "version": "4.0.0",
+  "author": "Simon Lydell",
+  "license": "MIT",
+  "description": "A regex that tokenizes JavaScript.",
+  "keywords": [
+    "JavaScript",
+    "js",
+    "token",
+    "tokenize",
+    "regex"
+  ],
+  "files": [
+    "index.js"
+  ],
+  "repository": "lydell/js-tokens",
+  "scripts": {
+    "test": "mocha --ui tdd",
+    "esprima-compare": "node esprima-compare ./index.js everything.js/es5.js",
+    "build": "node generate-index.js",
+    "dev": "npm run build && npm test"
+  },
+  "devDependencies": {
+    "coffeescript": "2.1.1",
+    "esprima": "4.0.0",
+    "everything.js": "1.0.3",
+    "mocha": "5.0.0"
+  }
+}