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/2021/AbstractRelationalComparison.js

@@ -0,0 +1,80 @@
+'use strict';
+
+var GetIntrinsic = require('get-intrinsic');
+
+var $Number = GetIntrinsic('%Number%');
+var $TypeError = require('es-errors/type');
+
+var $isNaN = require('math-intrinsics/isNaN');
+
+var IsStringPrefix = require('./IsStringPrefix');
+var StringToBigInt = require('./StringToBigInt');
+var ToNumeric = require('./ToNumeric');
+var ToPrimitive = require('./ToPrimitive');
+
+var BigIntLessThan = require('./BigInt/lessThan');
+var NumberLessThan = require('./Number/lessThan');
+
+var isSameType = require('../helpers/isSameType');
+
+// https://262.ecma-international.org/11.0/#sec-abstract-relational-comparison
+
+// eslint-disable-next-line max-statements, max-lines-per-function
+module.exports = function AbstractRelationalComparison(x, y, LeftFirst) {
+	if (typeof LeftFirst !== 'boolean') {
+		throw new $TypeError('Assertion failed: LeftFirst argument must be a Boolean');
+	}
+	var px;
+	var py;
+	if (LeftFirst) {
+		px = ToPrimitive(x, $Number);
+		py = ToPrimitive(y, $Number);
+	} else {
+		py = ToPrimitive(y, $Number);
+		px = ToPrimitive(x, $Number);
+	}
+	if (typeof px === 'string' && typeof py === 'string') {
+		if (IsStringPrefix(py, px)) {
+			return false;
+		}
+		if (IsStringPrefix(px, py)) {
+			return true;
+		}
+		return px < py; // both strings, neither a prefix of the other. shortcut for steps 3 c-f
+	}
+
+	var nx;
+	var ny;
+	if (typeof px === 'bigint' && typeof py === 'string') {
+		ny = StringToBigInt(py);
+		if ($isNaN(ny)) {
+			return void undefined;
+		}
+		return BigIntLessThan(px, ny);
+	}
+	if (typeof px === 'string' && typeof py === 'bigint') {
+		nx = StringToBigInt(px);
+		if ($isNaN(nx)) {
+			return void undefined;
+		}
+		return BigIntLessThan(nx, py);
+	}
+
+	nx = ToNumeric(px);
+	ny = ToNumeric(py);
+	if (isSameType(nx, ny)) {
+		return typeof nx === 'number' ? NumberLessThan(nx, ny) : BigIntLessThan(nx, ny);
+	}
+
+	if ($isNaN(nx) || $isNaN(ny)) {
+		return void undefined;
+	}
+	if (nx === -Infinity || ny === Infinity) {
+		return true;
+	}
+	if (nx === Infinity || ny === -Infinity) {
+		return false;
+	}
+
+	return nx < ny; // by now, these are both nonzero, finite, and not equal
+};