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/get-proto/index.js

@@ -0,0 +1,27 @@
+'use strict';
+
+var reflectGetProto = require('./Reflect.getPrototypeOf');
+var originalGetProto = require('./Object.getPrototypeOf');
+
+var getDunderProto = require('dunder-proto/get');
+
+/** @type {import('.')} */
+module.exports = reflectGetProto
+	? function getProto(O) {
+		// @ts-expect-error TS can't narrow inside a closure, for some reason
+		return reflectGetProto(O);
+	}
+	: originalGetProto
+		? function getProto(O) {
+			if (!O || (typeof O !== 'object' && typeof O !== 'function')) {
+				throw new TypeError('getProto: not an object');
+			}
+			// @ts-expect-error TS can't narrow inside a closure, for some reason
+			return originalGetProto(O);
+		}
+		: getDunderProto
+			? function getProto(O) {
+				// @ts-expect-error TS can't narrow inside a closure, for some reason
+				return getDunderProto(O);
+			}
+			: null;