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/workbox-build/package.json

@@ -0,0 +1,73 @@
+{
+  "name": "workbox-build",
+  "version": "7.4.0",
+  "description": "A module that integrates into your build process, helping you generate a manifest of local files that workbox-sw should precache.",
+  "keywords": [
+    "workbox",
+    "workboxjs",
+    "service worker",
+    "caching",
+    "fetch requests",
+    "offline",
+    "file manifest"
+  ],
+  "engines": {
+    "node": ">=20.0.0"
+  },
+  "author": "Google's Web DevRel Team and Google's Aurora Team",
+  "license": "MIT",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/googlechrome/workbox.git"
+  },
+  "bugs": "https://github.com/GoogleChrome/workbox/issues",
+  "homepage": "https://github.com/GoogleChrome/workbox",
+  "dependencies": {
+    "@apideck/better-ajv-errors": "^0.3.1",
+    "@babel/core": "^7.24.4",
+    "@babel/preset-env": "^7.11.0",
+    "@babel/runtime": "^7.11.2",
+    "@rollup/plugin-babel": "^5.2.0",
+    "@rollup/plugin-node-resolve": "^15.2.3",
+    "@rollup/plugin-replace": "^2.4.1",
+    "@rollup/plugin-terser": "^0.4.3",
+    "@surma/rollup-plugin-off-main-thread": "^2.2.3",
+    "ajv": "^8.6.0",
+    "common-tags": "^1.8.0",
+    "fast-json-stable-stringify": "^2.1.0",
+    "fs-extra": "^9.0.1",
+    "glob": "^11.0.1",
+    "lodash": "^4.17.20",
+    "pretty-bytes": "^5.3.0",
+    "rollup": "^2.79.2",
+    "source-map": "^0.8.0-beta.0",
+    "stringify-object": "^3.3.0",
+    "strip-comments": "^2.0.1",
+    "tempy": "^0.6.0",
+    "upath": "^1.2.0",
+    "workbox-background-sync": "7.4.0",
+    "workbox-broadcast-update": "7.4.0",
+    "workbox-cacheable-response": "7.4.0",
+    "workbox-core": "7.4.0",
+    "workbox-expiration": "7.4.0",
+    "workbox-google-analytics": "7.4.0",
+    "workbox-navigation-preload": "7.4.0",
+    "workbox-precaching": "7.4.0",
+    "workbox-range-requests": "7.4.0",
+    "workbox-recipes": "7.4.0",
+    "workbox-routing": "7.4.0",
+    "workbox-strategies": "7.4.0",
+    "workbox-streams": "7.4.0",
+    "workbox-sw": "7.4.0",
+    "workbox-window": "7.4.0"
+  },
+  "main": "build/index.js",
+  "workbox": {
+    "packageType": "node_ts"
+  },
+  "types": "build/index.d.ts",
+  "devDependencies": {
+    "@types/node": "^20.14.8"
+  },
+  "gitHead": "fa702feeddd417fcdfa495cd9428fb4a28632e92"
+}