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/async-function/CHANGELOG.md

@@ -0,0 +1,16 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## v1.0.0 - 2025-01-22
+
+### Commits
+
+- Initial implementation, tests, readme, types [`8ad64e4`](https://github.com/ljharb/async-function/commit/8ad64e45668359cf032e095afcbe6ef0d291d6b4)
+- Initial commit [`36dac0d`](https://github.com/ljharb/async-function/commit/36dac0de439b8b6d7af6a246cf984b087efaaf87)
+- [meta] reformat `package.json` [`11ff004`](https://github.com/ljharb/async-function/commit/11ff0044813122c6d22e3bf360af979f7c3f7fc8)
+- first publish [`5ed020c`](https://github.com/ljharb/async-function/commit/5ed020c7852e90f280517a06e4a4d3cb1d295e40)
+- Only apps should have lockfiles [`b746134`](https://github.com/ljharb/async-function/commit/b74613407f749720b7d02b26b9fb2093a0124878)