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/operations/es5.js

@@ -0,0 +1,50 @@
+'use strict';
+
+module.exports = {
+	'Abstract Equality Comparison': 'https://262.ecma-international.org/5.1/#sec-11.9.3',
+	'Abstract Relational Comparison': 'https://262.ecma-international.org/5.1/#sec-11.8.5',
+	'Strict Equality Comparison': 'https://262.ecma-international.org/5.1/#sec-11.9.6',
+	abs: 'http://262.ecma-international.org/5.1/#sec-5.2',
+	Canonicalize: 'https://262.ecma-international.org/5.1/#sec-15.10.2.8',
+	CheckObjectCoercible: 'https://262.ecma-international.org/5.1/#sec-9.10',
+	DateFromTime: 'https://262.ecma-international.org/5.1/#sec-15.9.1.5',
+	Day: 'https://262.ecma-international.org/5.1/#sec-15.9.1.2',
+	DayFromYear: 'https://262.ecma-international.org/5.1/#sec-15.9.1.3',
+	DaysInYear: 'https://262.ecma-international.org/5.1/#sec-15.9.1.3',
+	DayWithinYear: 'https://262.ecma-international.org/5.1/#sec-15.9.1.4',
+	floor: 'http://262.ecma-international.org/5.1/#sec-5.2',
+	FromPropertyDescriptor: 'https://262.ecma-international.org/5.1/#sec-8.10.4',
+	HourFromTime: 'https://262.ecma-international.org/5.1/#sec-15.9.1.10',
+	InLeapYear: 'https://262.ecma-international.org/5.1/#sec-15.9.1.3',
+	IsAccessorDescriptor: 'https://262.ecma-international.org/5.1/#sec-8.10.1',
+	IsCallable: 'https://262.ecma-international.org/5.1/#sec-9.11',
+	IsDataDescriptor: 'https://262.ecma-international.org/5.1/#sec-8.10.2',
+	IsGenericDescriptor: 'https://262.ecma-international.org/5.1/#sec-8.10.3',
+	IsPropertyDescriptor: 'https://262.ecma-international.org/5.1/#sec-8.10',
+	MakeDate: 'https://262.ecma-international.org/5.1/#sec-15.9.1.13',
+	MakeDay: 'https://262.ecma-international.org/5.1/#sec-15.9.1.12',
+	MakeTime: 'https://262.ecma-international.org/5.1/#sec-15.9.1.11',
+	MinFromTime: 'https://262.ecma-international.org/5.1/#sec-15.9.1.10',
+	modulo: 'https://262.ecma-international.org/5.1/#sec-5.2',
+	MonthFromTime: 'https://262.ecma-international.org/5.1/#sec-15.9.1.4',
+	msFromTime: 'https://262.ecma-international.org/5.1/#sec-15.9.1.10',
+	SameValue: 'https://262.ecma-international.org/5.1/#sec-9.12',
+	SecFromTime: 'https://262.ecma-international.org/5.1/#sec-15.9.1.10',
+	SplitMatch: 'https://262.ecma-international.org/5.1/#sec-15.5.4.14',
+	TimeClip: 'https://262.ecma-international.org/5.1/#sec-15.9.1.14',
+	TimeFromYear: 'https://262.ecma-international.org/5.1/#sec-15.9.1.3',
+	TimeWithinDay: 'https://262.ecma-international.org/5.1/#sec-15.9.1.2',
+	ToBoolean: 'https://262.ecma-international.org/5.1/#sec-9.2',
+	ToInt32: 'https://262.ecma-international.org/5.1/#sec-9.5',
+	ToInteger: 'https://262.ecma-international.org/5.1/#sec-9.4',
+	ToNumber: 'https://262.ecma-international.org/5.1/#sec-9.3',
+	ToObject: 'https://262.ecma-international.org/5.1/#sec-9.9',
+	ToPrimitive: 'https://262.ecma-international.org/5.1/#sec-9.1',
+	ToPropertyDescriptor: 'https://262.ecma-international.org/5.1/#sec-8.10.5',
+	ToString: 'https://262.ecma-international.org/5.1/#sec-9.8',
+	ToUint16: 'https://262.ecma-international.org/5.1/#sec-9.7',
+	ToUint32: 'https://262.ecma-international.org/5.1/#sec-9.6',
+	Type: 'https://262.ecma-international.org/5.1/#sec-8',
+	WeekDay: 'https://262.ecma-international.org/5.1/#sec-15.9.1.6',
+	YearFromTime: 'https://262.ecma-international.org/5.1/#sec-15.9.1.3'
+};