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/gensync/package.json

@@ -0,0 +1,37 @@
+{
+  "name": "gensync",
+  "version": "1.0.0-beta.2",
+  "license": "MIT",
+  "description": "Allows users to use generators in order to write common functions that can be both sync or async.",
+  "main": "index.js",
+  "author": "Logan Smyth <loganfsmyth@gmail.com>",
+  "homepage": "https://github.com/loganfsmyth/gensync",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/loganfsmyth/gensync.git"
+  },
+  "scripts": {
+    "test": "jest"
+  },
+  "engines": {
+    "node": ">=6.9.0"
+  },
+  "keywords": [
+    "async",
+    "sync",
+    "generators",
+    "async-await",
+    "callbacks"
+  ],
+  "devDependencies": {
+    "babel-core": "^6.26.3",
+    "babel-preset-env": "^1.6.1",
+    "eslint": "^4.19.1",
+    "eslint-config-prettier": "^2.9.0",
+    "eslint-plugin-node": "^6.0.1",
+    "eslint-plugin-prettier": "^2.6.0",
+    "flow-bin": "^0.71.0",
+    "jest": "^22.4.3",
+    "prettier": "^1.12.1"
+  }
+}