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/is-bigint/test/index.js

@@ -0,0 +1,65 @@
+'use strict';
+
+var test = require('tape');
+var inspect = require('object-inspect');
+var hasBigInts = require('has-bigints')();
+var hasToStringTag = require('has-tostringtag/shams')();
+var forEach = require('for-each');
+var v = require('es-value-fixtures');
+
+var isBigInt = require('../');
+
+test('non-BigInt values', function (t) {
+	/** @type {(typeof v.primitives[number] | object)[]} */
+	var nonBigInts = v.nonBigInts.concat(
+		Object(true),
+		Object(false),
+		// @ts-expect-error TS sucks with concat
+		{},
+		[],
+		/a/g,
+		new Date(),
+		function () {},
+		NaN,
+		v.symbols
+	);
+	t.plan(nonBigInts.length);
+	forEach(nonBigInts, function (nonBigInt) {
+		t.equal(false, isBigInt(nonBigInt), inspect(nonBigInt) + ' is not a BigInt');
+	});
+	t.end();
+});
+
+test('faked BigInt values', function (t) {
+	t.test('real BigInt valueOf', { skip: !hasBigInts }, function (st) {
+		var fakeBigInt = { valueOf: function () { return BigInt(42); } };
+		st.equal(false, isBigInt(fakeBigInt), 'object with valueOf returning a BigInt is not a BigInt');
+		st.end();
+	});
+
+	t.test('faked @@toStringTag', { skip: !hasBigInts || !hasToStringTag }, function (st) {
+		/** @type {{ valueOf(): unknown; [Symbol.toStringTag]?: unknown }} */
+		var fakeBigInt = { valueOf: function () { return BigInt(42); } };
+		fakeBigInt[Symbol.toStringTag] = 'BigInt';
+		st.equal(false, isBigInt(fakeBigInt), 'object with fake BigInt @@toStringTag and valueOf returning a BigInt is not a BigInt');
+
+		/** @type {{ valueOf(): unknown; [Symbol.toStringTag]?: unknown }} */
+		var notSoFakeBigInt = { valueOf: function () { return 42; } };
+		notSoFakeBigInt[Symbol.toStringTag] = 'BigInt';
+		st.equal(false, isBigInt(notSoFakeBigInt), 'object with fake BigInt @@toStringTag and valueOf not returning a BigInt is not a BigInt');
+		st.end();
+	});
+
+	var fakeBigIntString = { toString: function () { return '42n'; } };
+	t.equal(false, isBigInt(fakeBigIntString), 'object with toString returning 42n is not a BigInt');
+
+	t.end();
+});
+
+test('BigInt support', { skip: !hasBigInts }, function (t) {
+	forEach(v.bigints.concat(Object(BigInt(42))), function (bigInt) {
+		t.equal(true, isBigInt(bigInt), inspect(bigInt) + ' is a BigInt');
+	});
+
+	t.end();
+});