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/@vitest/expect/package.json

@@ -0,0 +1,47 @@
+{
+  "name": "@vitest/expect",
+  "type": "module",
+  "version": "2.1.9",
+  "description": "Jest's expect matchers as a Chai plugin",
+  "license": "MIT",
+  "funding": "https://opencollective.com/vitest",
+  "homepage": "https://github.com/vitest-dev/vitest/tree/main/packages/expect#readme",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/vitest-dev/vitest.git",
+    "directory": "packages/expect"
+  },
+  "bugs": {
+    "url": "https://github.com/vitest-dev/vitest/issues"
+  },
+  "sideEffects": false,
+  "exports": {
+    ".": {
+      "types": "./index.d.ts",
+      "default": "./dist/index.js"
+    },
+    "./*": "./*"
+  },
+  "main": "./dist/index.js",
+  "module": "./dist/index.js",
+  "types": "./index.d.ts",
+  "files": [
+    "*.d.ts",
+    "dist"
+  ],
+  "dependencies": {
+    "chai": "^5.1.2",
+    "tinyrainbow": "^1.2.0",
+    "@vitest/spy": "2.1.9",
+    "@vitest/utils": "2.1.9"
+  },
+  "devDependencies": {
+    "@types/chai": "4.3.6",
+    "rollup-plugin-copy": "^3.5.0",
+    "@vitest/runner": "2.1.9"
+  },
+  "scripts": {
+    "build": "rimraf dist && rollup -c",
+    "dev": "rollup -c --watch"
+  }
+}