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/runner/dist/utils.js

@@ -0,0 +1,4 @@
+export { a as calculateSuiteHash, c as createChainable, b as createFileTask, g as generateHash, d as getFullName, e as getNames, f as getSuites, h as getTasks, j as getTestName, k as getTests, m as hasFailed, n as hasTests, i as interpretTaskModes, o as isAtomTest, l as limitConcurrency, p as partitionSuiteChildren, s as someTasksAreOnly } from './chunk-tasks.js';
+import '@vitest/utils/error';
+import 'pathe';
+import '@vitest/utils';