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/punycode/package.json

@@ -0,0 +1,58 @@
+{
+  "name": "punycode",
+  "version": "2.3.1",
+  "description": "A robust Punycode converter that fully complies to RFC 3492 and RFC 5891, and works on nearly all JavaScript platforms.",
+  "homepage": "https://mths.be/punycode",
+  "main": "punycode.js",
+  "jsnext:main": "punycode.es6.js",
+  "module": "punycode.es6.js",
+  "engines": {
+    "node": ">=6"
+  },
+  "keywords": [
+    "punycode",
+    "unicode",
+    "idn",
+    "idna",
+    "dns",
+    "url",
+    "domain"
+  ],
+  "license": "MIT",
+  "author": {
+    "name": "Mathias Bynens",
+    "url": "https://mathiasbynens.be/"
+  },
+  "contributors": [
+    {
+      "name": "Mathias Bynens",
+      "url": "https://mathiasbynens.be/"
+    }
+  ],
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/mathiasbynens/punycode.js.git"
+  },
+  "bugs": "https://github.com/mathiasbynens/punycode.js/issues",
+  "files": [
+    "LICENSE-MIT.txt",
+    "punycode.js",
+    "punycode.es6.js"
+  ],
+  "scripts": {
+    "test": "mocha tests",
+    "build": "node scripts/prepublish.js"
+  },
+  "devDependencies": {
+    "codecov": "^3.8.3",
+    "nyc": "^15.1.0",
+    "mocha": "^10.2.0"
+  },
+  "jspm": {
+    "map": {
+      "./punycode.js": {
+        "node": "@node/punycode"
+      }
+    }
+  }
+}