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/pretty-bytes/package.json

@@ -0,0 +1,47 @@
+{
+	"name": "pretty-bytes",
+	"version": "6.1.1",
+	"description": "Convert bytes to a human readable string: 1337 → 1.34 kB",
+	"license": "MIT",
+	"repository": "sindresorhus/pretty-bytes",
+	"funding": "https://github.com/sponsors/sindresorhus",
+	"author": {
+		"name": "Sindre Sorhus",
+		"email": "sindresorhus@gmail.com",
+		"url": "https://sindresorhus.com"
+	},
+	"type": "module",
+	"exports": "./index.js",
+	"types": "./index.d.ts",
+	"engines": {
+		"node": "^14.13.1 || >=16.0.0"
+	},
+	"scripts": {
+		"test": "xo && ava && tsd"
+	},
+	"files": [
+		"index.js",
+		"index.d.ts"
+	],
+	"keywords": [
+		"pretty",
+		"bytes",
+		"byte",
+		"filesize",
+		"size",
+		"file",
+		"human",
+		"humanized",
+		"readable",
+		"si",
+		"data",
+		"locale",
+		"localization",
+		"localized"
+	],
+	"devDependencies": {
+		"ava": "^4.0.1",
+		"tsd": "^0.19.1",
+		"xo": "^0.54.0"
+	}
+}