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/es-abstract/2024/ByteListBitwiseOp.js

@@ -0,0 +1,39 @@
+'use strict';
+
+var $TypeError = require('es-errors/type');
+
+var IsArray = require('./IsArray');
+
+var isByteValue = require('../helpers/isByteValue');
+
+// https://262.ecma-international.org/12.0/#sec-bytelistbitwiseop
+
+module.exports = function ByteListBitwiseOp(op, xBytes, yBytes) {
+	if (op !== '&' && op !== '^' && op !== '|') {
+		throw new $TypeError('Assertion failed: `op` must be `&`, `^`, or `|`');
+	}
+	if (!IsArray(xBytes) || !IsArray(yBytes) || xBytes.length !== yBytes.length) {
+		throw new $TypeError('Assertion failed: `xBytes` and `yBytes` must be same-length sequences of byte values (an integer 0-255, inclusive)');
+	}
+
+	var result = [];
+
+	for (var i = 0; i < xBytes.length; i += 1) {
+		var xByte = xBytes[i];
+		var yByte = yBytes[i];
+		if (!isByteValue(xByte) || !isByteValue(yByte)) {
+			throw new $TypeError('Assertion failed: `xBytes` and `yBytes` must be same-length sequences of byte values (an integer 0-255, inclusive)');
+		}
+		var resultByte;
+		if (op === '&') {
+			resultByte = xByte & yByte;
+		} else if (op === '^') {
+			resultByte = xByte ^ yByte;
+		} else {
+			resultByte = xByte | yByte;
+		}
+		result[result.length] = resultByte;
+	}
+
+	return result;
+};